 Είναι ο εργασίας που είμαστε εργασίας. Γεια σας, καλώς είμαστε εργασίας και καλώς είμαστε εργασίας της Σεμίναρς της ΑΕΕΡΙΣ. Είμαι ο Γιώργος Καφετζής, και είμαι ο Μαστις Γραδιόνς, από το Τόμμα Σολιερστό Βουλίου και τώρα ένας ΠΕΡΙΣ' με τον Τόμ Μπανδεν. Και όπως είμαι ο χώρος για σήμερα, θα ήθελα να ξεκινήσω να εγγράψω τον Πανός Μποζέλος με την εξαναγωγή εργασίας για την Ευρωπαϊκή Βουλίου και το Παρασμένο Σεμίναρ. Αυτό, αλλαγωγή, να πάμε για την στιγμή που είμαστε εργασίας για στιγμή μας, και να δούμε το μυαλό της Βουλίου και τη Μουσίου Φουχ-να-τουχ Κούντε, Λόγος Λόρων, Σέμπνερα, Λόγος Βουλίου και την Ευρωπαϊκή Βουλίου για την Ευρωπασία, και την Σεμίναρ, ε 굉장ή μέρη της Γιουλίας Τσίγουρτ στην Κυντσύνη στη Βελφάστα, και σαν καρδόμα της Παρασμένος με την σχήμα της Ευρωπαϊκής Βουλίου και την Ευρωπαϊκή Βουλίου. Από τηplan, και τη Γερμανία, και τη Μουσίου Φουχ-να-τουχ Κούντε σαν τη βαστιά της Βουλ sollenτασία. Γενικά της Βουλίου έρθει στη βιζιώνα στο 혼ελίου, το 2017, Τελευταία χρόνια, που βρίσκει στον Βουγνούχο του Κουνδένου, που είναι ο Βουγνούχο για τη Συντασία Βασικού, όχι με τον Γερμαν, στις εξένειες, έτσι, όπως ένα γιναιογραφότητας της Συντασίας, ξεχνάς τη Συντασία και παρακολουθώ να το χρησιμοποιήσω. Είναι πολύ αλήθεια να έχουμε να μην εξεγώσει στις εξένειες, μιλάμε για να μην εξεγώσουμε στις εξεγώσεις ή αγγελματές στις εξεγώσεις, και εξεγώσουμε συγκεκριμένως με πολλές άνειες στην οδηγία, δεν μπορώ να δούμε πώς δεξανόνται ή ξεχνάς αυτές τις εξεγώσεις, και γιατί κάποιες άνθρωποι έχουν περισσότερες δύσκολες. Δεν υπάρχει τίποτα να κάνω από μου, ευχαριστώ να δώσει τον Σάμμναι Ρούνι. Λόγω σε αυτή η στιγμή όλοι σας. Ευχαριστώ πολύ για την παράδειγμα, και φυσικά για την εμπειρία εδώ σήμερα. Εγώ είμαι πολύ εύκολη για να μιλήσω σε όλο. Και καλύτερα καλύτερα, καλύτερα or evening, πιστεύω πάνω όπου είσαι. Λοιπόν, όπως ο Γιώργος είπα, δε θα πω πίσω πέρα για ένα μεγάλο ζήτημα, αλλά έρχεται για πάνω και τελευταία λόγια, όσο ήρθω στον Σάμμναι Ρούνι, για να πω αξιωμή μου. Ας δείξω, ну, πέρασασαν σε αυτό το κομμάτι, και πω ότι η διότητα είναι ένα πολύ σημαντικό σώμα. Έτσι, η Λόγω είναι πλέον πολύ σημαντική για την υπιεργία. Στους Λόγω, όλα οι ίδιοι για όλες οι προσπήσεις, είναι πολύ βάσιμα, Προσπαθούντας να είναι η σημαντική μυαλόγηση. Λοιπόν, όχι μόνο πράγματα like, φορυγή, μεταφάλλοντας, κοινότητας οικογένωσης, οικογένωσης και οικογένωσης. Βιζιόντας και λίχτας έχουν αρκετή φορυγή για όλες τις ασφαλές της οικογένωσης και της οικογένωσης. Αυτό είναι το βιζιόντας αυτό, είναι αυτό μεγάλο. Λόγον, σκέφτερα για να αντιμετωπίσω. Δεν ξέρω, θα αρέσεις να ξεκινήσεις το σκέφτερα ή αυτό είναι πραγματικό. Α, θα αφήσω το σκέφτερα. Ευχαριστώ για την προσπαθή. Αλλά όμως μπορείς να εξηγήσετε μια εξηγή δημιουργία και μεταφάλλοντας που μπορείς να δείτε στον εμπορύγιο. Έτσι, δώσ' μου να προσπαθώ αυτό πραγματικά και ευχαριστώ, George. Λοιπόν, πράγματα. Επίσης μπορείς να δείτε έναν ασφαλήριο, εξηγή δημιουργία και μεταφάλλοντας. Λοιπόν, ας πέναμε, δημιουργήσαμε αυτή η δημιουργία που εξηγήσαμε, το οποίο εξηγήσε το επικορύγιο με δημιουργία και μεταφάλλοντας πραγματικά 40-χορδιά. Αυτό είναι ένας πολύ καταλείδος εξηγοστανής προδέσκησης, δημιουργία συμφωνή, αλλά όσο έχει εξηγή για δημιουργία, δημιουργία, εξηγή και κορδία βάδυ, επίσης, και αυτό είναι έναν δημιουργία που εξηγήσε τίποτας. Βεβαίνοντας στους παιδιάς μας, η δημιουργία έχει ασφαλήθει τη δημιουργία σε δημιουργίες και ανθρώπους για πολύ λόγες φορές. Μπορείτε να δείτε κάποιες από τα 17ο και 18ο χρόνια, καλύτερα δημιουργείται, όχι μόνο ανθρώπους, αλλά και όμως όμως ανθρώπους. Αλλά η δημιουργία της δημιουργίας είναι πρόσφυγησης για έναν πιτικό τρόπο της δημιουργίας. Αυτό είναι η δημιουργία της δημιουργίας. Βνήθως αυτό είναι το πιο ξανάμενο για εμάς, αλλά είναι δημιουργίας για τα διάρκεια των χρόνων. Βανθώς, δημιουργείς ότι we understand the advantages και ότι η δημιουργία είναι πολύ καλύτερη. Δημιουργείς από τη στεριοσκοφή και την δεύτερη προσφαλή, για να έχουμε ένα δημιουργείο εξαφαλής και χαρδόση, να έχουμε δύο παιδιά όπως να βάθουμε όλες τα ασφαλήθει, όπως ήταν. Αλλά είναι για τη δημιουργία που δημιουργείς. Βέβαια, αυτό δεν είναι νέο, αυτό δεν είναι κάτι που έχω διεθνώσει. Έτσι, είχαμε γνώριση σε πολλές από αυτές τις συμφωνές, ή σε καλύτερες σκολογές που βρίσκονται στις δυο πρόσφυρες που βρίσκονται στις δυσκολογές. Φυσικά, όχι μόνος πλήκος, όπως αυτό που βρίσκονται στις δυσκολογές, και μετά από πράγματα, έχουμε ένα καλύτερο μονοδοστασμό για να επαναστάξουμε πράγματα. Λοιπόν, ένα παράδειγμα, σκαλαβές, τα οποία were first described in 1795, they're very distinctive, and of course they're in an animal that's accessible and delicious, so we know quite a lot about them. We also know a lot about the structure of individual eyes, including some vision by the behaviors, and actually we're now starting to have a discussion about how integration occurs between eyes and systems like this. This is very challenging, obviously the more eyes you have, the more units you're integrating, the more difficult this is, that we are starting to see some really nice experimental work looking at this. So in the example of scallops, there was a great paper from Dan Chappelle at the end of last year looking at how different eyes might be communicating and the difference between spatial vision and spatial resolution. So although we've known about a lot of these systems kind of in isolation, or we've been studying them in isolation, actually the use of phrases like distributed vision or dispersed vision are actually relatively recent. So in the last kind of 10, 20 years, more and more conversation has been happening about what these systems are overall. There's wider conversation about why they're involved, and this is basically what I'm hoping to address a lot of other people in our new group in Berlin. So although for specific questions, we're inevitably taking a model-based approach, what we do want is to have a kind of broader conversation about conceptual questions and links between all these very different systems. So really starting at the top, we want to answer some pretty basic questions about some of these things actually, and you'd be surprised that we don't necessarily have the answers immediately accessible to some of these questions. So for example, where do these actually occur? I struggled to find a nice neat list of all of the filer in which you can find these many eyed visual systems. And are they kind of unifying features? Are there functional principles that kind of govern the relationships between different characters of these systems? And are there specific ecological or developmental correlates, as there are for lots of other aspects of binocular systems, for example? So the first thing to do, like I said, is actually just to kind of try and survey the annual kingdom in its broadest sense and establish exactly where and when these visual systems appear. So what we did was actually, and this is ongoing, we did was look at all filer that have more than a thousand described species. Obviously a lot of these structures have not been tested specifically to work out whether they are in fact eyes in the sense that they convey spatial resolution. So we've taken quite a generous approach to this and included any structure that has more than two photoreceptors and it has screening pigment. So as a kind of very, very basic possibility of discerning which direction that light is coming from and we're looking at adult structures only. So one of the things that we've done is try and then extract data about all of those different visual systems, the number of eyes, the number of eye types, their diameter, body size, and a couple of basics to do photoreceptor length or interreceptor angle and diameter. So what we found is that, you know, this common perception of many eye systems being peripheral or unrepresentative is actually quite a misrepresentation. So these systems actually occur in seven out of the 10 largest animal filer and the remaining three of those don't have eyes at all as adults. So actually they're pretty ubiquitous amongst any firm that has eyes in any case. They're also in at least nine out of the 16 filer that contain more than 1000 species. And they obviously also appear in the fossil record more than a half a billion years ago. So these are not unusual, even though they seem alien to us, they're actually a very common solution to the evolutionary problem with vision. One of the things that has actually kind of emerged from this and I'm not going to give you a rundown of all of these systems we'd be here all night. But what has kind of emerged is these three broad classifications that we kind of propose adopting in future conversations about many eye systems. So first of all, you have duplicated systems. So this is where you have many replicated units that have shared developmental origins and to collect broadly similar or the same information. So examples might include the scallops that we already discussed, perhaps chitin shell eyes and the optic Christians of sea stars as well. This is just where you have a single type of visual system, but perhaps it's multiplied or spread across the entire body. The second type is parallel visual systems. So this is where I'm kind of talking about having more than one type of eye with distinct developmental origins and presumably collecting different visual information. So the best known of these, of course, would be the insect SLI and compound eyes. But then you also have things like the box jellyfish and their six eye types on their rupalia, as well as versus briot parietal eyes or shoe crowds, etc. Finally, we have this somewhat kind of enigmatic category, which you could argue, does it fit into the whole concept of being a many eye system. What we have here is extra ocular systems. So we're in an animal lacks a discrete visual structure dedicated organ and actually has both receptors spread across the whole body. This obviously in itself occurs in quite a lot of different systems, but we only have direct experimental evidence for spatial resolution from those systems and a couple of different species. So for now, it's only been described in a couple of the kind of germs, but it's highly likely that there may be other groups as well that could eventually fall into this category. So they're both very widespread, and they also appear to be have to have multiple origins as well. So the numbers and parentheses here are just estimates of how many potential origins that probably are according to the position of these different systems in animal phylogeny. So what about these functional and ecological relationships then. So we started to have a look at some of those data I talked about things like my number i diameter, but as I said an ongoing process so do bear with me. These are kind of first pass visualizations to get an idea of what's happening in the data and hopefully this will be published more formally as a review later this year. We do have additional final to add still, and then we can perform proper phylogenetically corrected models, but I do think there is interesting leads and I just wanted to kind of share them with you and also get your thoughts as well. So my functional principles I actually kind of mean basic relationships between different characters with visual systems so within single eyes, for example, we know that there are often trade offs between resolution sensitivity and ice eyes among many many other factors. And I suppose comparatively to thinking about binocular systems, we know that the spectrum of kind of field of view coverage versus depth perception can have links to to trophic model. So in these many items systems there are a few new variables to consider here I suppose so we might expect to see relationships between i number by size number of itypes. And of course there are going to be evolutionary factors or constraints and ecological factors to include as well. So as I said, they're kind of still gathering data on this but so far we've got 126 species from eight different final with more being added more time. So it started to get handled on some of these relationships and they're kind of very, very basic form so for example, unsurprisingly perhaps i number and i diameter have a show quite strong inverse relationship. I think this is perfectly logical you can imagine you'd make a greater investment in fewer eyes or less investment in more eyes. So these are examples for both absolute my size which of course is functionally important to things like sensitivity and resolution, and of course to relative i diameter as well so adjusted for body size. Obviously, as I said it's important to note that this doesn't include phylogeny in the model yet, but actually if you unpick it by filing this relationship broadly carries. Some of those phylogeny do have quite a nice coverage of i number as well. So as an example, again, this is not necessarily new knowledge but this slide of my box really nicely demonstrates this concept in some of his statements. So this idea of either having distributed eyes which often be much smaller and spread across a larger part of the body versus consolidating all of your investment into two much larger, possibly more powerful eyes there. But if we see this multiple phylogeny then perhaps it's a broader principle of these duplicated systems anyway. So the next thing we actually looked at was whether or not body size affects any of these things so what we found is that parallel systems are actually more common smaller taxa so. Again, this makes sense seems fairly logical results so if you imagine a smaller animal might find it more energetically economical to split tasks between several smaller eyes, rather than having fewer large eyes. So I guess doubling investment by adding an extra eye the same size might be more economical than increasing the volume of an eye by a factor of two. And actually there's a quite a nice analogy on this from I think I might have frozen. I hope not. Can you still hear me? Yeah, we can hear you crystal clear. Good fine. You froze so I was worried that I might have dropped out of my internet there. So actually, in some of the best targeting advertising I've received in my entire life, Samsung have actually really nicely summarized this concept. So what we now see increasingly in smartphones, for example, is that actually you can't buy something that has fewer than four cameras but all four of those cameras are adjusted to do a slightly different job. So when you have these kinds of size constraints and space constraints, it might be more economical to produce more than one eye type than it is to make a larger eye that can do more. So potentially tied to this other kind of eye sign is i number relationship we also see fewer eyes overall where you have more types of eyes so in parallel systems. This is probably going to be affected once more vertebrate data added, but it does seem to at least seems that i number become less variable as you increase the number of parallel systems. So certainly ecological factors and activity and trophic level boasting to affect i number and of course they're almost certainly linked to one another as well. And so cessile species and and those that are primary consumers seems to generally speaking have more eyes than either their mobile or their higher trophic level counterparts. We didn't see any impact of things like body symmetry. We did see a difference between having more eyes in aquatic than terrestrial taxa. But of course there's much greater representation. Very much greater phylogenetic representation in aquatic. So that's a bit of a confirmed factor there. Then again kind of closely linked to suppose we actually do see the opposite effect. So those that those taxes that move in three dimensions or moving more quickly have substantially larger eyes than their counterparts and again terrestrial animals do as well. Finally, looking at the links between for example ecological factors and the number of i types this requires a bit more a bit more work a bit more data, but we do seem to see a couple of patterns. So for example, and cessile and swimming animals and more likely to have just one or two i types and the same. Sorry, yeah, both locomotion and speed seem to affect the number of i types that could be present. So from all of these things, we kind of have a spectrum emerging perhaps to consider for many items systems so things really stretching from having many small eyes of one or a few types. All the way through to having fewer larger eyes of different types collecting different information. And they do seem to be pretty logical and fairly strong coronations there with both trophic level and with activity level as well. Obviously again there's a kind of biogenetic element here so we do have something of an over representation of our records and vertebrates where you have their prior to eyes at one end and the marine invertebrate texture at the other end. The three categories that we've identified earlier also collectively follow along the spectrum, obviously there's some overlap. There are plenty of examples of species that have both duplicated and parallel visual systems so they can fall into this gray area in the middle. So today, one of the things I want to do next is actually look a bit more closely at some of these factors. Eye size, eye function and ecology evolution. So to tackle more specific questions and exactly how these systems function and evolve, it obviously helps to constrain yourself to one or a few groups. So for me spiders are really the kind of a really great model for this. So they occupy a spread on this kind of theoretical spectrum that we've spoken about, but they also exhibit a range of different visual ecologies. They have both parallel and duplicated systems, and they have very constrained blueprints, they're kind of anatomy. So what I'm talking about next is how then spiders have exploited this ability to use more than two eyes. This is where I warn you that you're about to see a lot of closer pictures of spiders. Anybody who's not particularly a fan of that, I will, you know, fly up when they're gone so you can look back at the computer screen, but particularly when I was doing in-person seminars I found that this warning became very helpful. So without further ado, this is some of the beautiful diversity that we see in spider visual systems. So as I said, they've got an enormous variety in size, arrangement and ecology as well. So you can see that there's a multitude of different evolutionary groups that spiders are taking to having this quite constrained visual system. The spider photos are now mostly gone. But as I said, they all use quite conserved blueprints. So as a quick primer, I have this beautiful illustration of name wallhouses, which I can't improve upon, so I'll just use it. So they have two types of eyes and usually have four pairs. They have the principal eyes with an averse retina, and the secondary eyes usually with a torpedo and the inverse retina on the right-hand side. And we do see a really beautiful array of different arrangements, but we also see different visual ecologies, with our visual hunters, free running hunters, and of course web-based hunters. We do see some kind of like very superficial correlations with their visual system structure as well. So the first challenge is obviously understanding what it is that they're actually seeing. So what information every animal collects, what information every pair of eyes collects. But only a very small number of species have been studied in great detail so far. Then I'm kind of interested in testing some of the principles that we identified in that kind of broader survey. Do they hold up if you're just looking at a constrained system both in terms of eye number and in terms of phylogeny? And otherwise, how much of that spectrum is actually just a phylogenetic artifact? And then finally, what are the kind of nuts and bolts of changing these visual systems so dramatically? So obviously thanks to more the century of really excellent vision research on binocular animals, we have a really great understanding of some of the relationships between morphology and function. Obviously in animal vision, these are quite closely related as a combination of optical and biological constraints, which is great. I mean, it means for us that we can learn quite a lot from structure. And actually, we can kind of make inferences about four out of five of the major functional properties of the visual system. We obviously can't make any inferences that way. But we can certainly have a kind of good level of understanding at least a comparative sense of those other four qualities. So for some of these structural studies, we've used a technique called synchrotron tomography, which some of you will be familiar with. It's very similar to micro CT. It's much, it's much more powerful. So the scans are much faster. It uses more specific x-ray energies as well. So you can end up with better resolution and greater contrast enhance them. So just to give you an idea of what we produce, hopefully you'll be able to see a scan of a wolf spider right now. And you can see that you're passing through some of the iPairs there, appearing in the middle. So given that that's, you know, that total field with you is only a few million, just across. We've got really beautiful, high power, high resolution scans and a lot of information there of each scan, only taking about eight minutes. So if we zoom into one of the particular eyes here, what you will hopefully be able to see, realize now that you probably can't see my cursor. But hopefully you can see my cursor. Wonderful. Hopefully down here you can see a beautiful striker region where we've actually got the individual raddoms here that you can see passing between the pigment here. So actually you can make out the raddoms of individual photoreceptors. You'll notice that this edge, they're pretty wide and the middle, they're very fine. So we're actually starting to see, you know, differences in the retinal mosaic, just to remove kind of more scan data, which is really exciting. So again, many of you could be familiar with these techniques, but we're using these data then to generate 3D models, so we can actually look at the lens and the retina, particularly in their full kind of 3D context. So what we can do then is extract a huge amount of information about each eye, each species, and as I said, at least have a decent inference as to function in a comparative sense. So looking at comparing eyes and comparing species. So for example here, we can see that these two eyes, the posterior median and posterior lateral, may well be collecting similar information. So they've got small intercept angles, long raddoms, and a fairly high proportion of lens diameter thickness for greater focusing power. It's likely that compared to the other two pairs, these eyes are more built for detail. And it's important to note here that they do also point in different directions. By contrast, if you look at the principal eyes, the AMEs, they're much smaller. Their field of view overlaps pretty much completely with the posterior median eyes, but they look like they're probably collecting different information. So here we have a much larger intercept angle, probably less focusing power, but we do have potential polarization sensitivity in this kind of tiered retina, where the two layers are oriented perpendicular to one another. So again, they're sampling perhaps the same space as the posterior median eyes, but they're extracting different information. So you can actually extract a lot of information from these measurements, but getting good data out of these retinal characters can be very, very slow. So a big part of my group's work is going to be moving towards semi-automated analysis of retinal rosic structure. So thanks to collaborators like Dr. Pablo Correa at UCLA, you're actually generating a pipeline to extract much more detailed information from these reconstructed scans. So for example, this is just one eye of a crab spider, but you can see just from looking at these kind of retinal maps, that you have clear regional differences in eye structure, as we saw from that example scan that I showed you. So for example, we have this kind of mid band of smaller cross-sectional area of the radians, lower skewness, and a smaller intercept angle. So presumably again, let's come back across the horizon of the eye. And that's also at the point where the retina is furthest from the lens and probably has again the great best focus. But for now, we're working with our data to be extracted manually, but we can still see that there's quite a different range of possible visual abilities and that different eye pairs do behave differently from different species. So for example, there's a tendency for the anterior and median eyes to have the finest potential resolution. And also we're kind of seeing outliers in a lot of these characteristics of visual contours. So these two are highlighting jumping spiders and wolf spiders. And you can see that they actually kind of are sitting quite a long way outside the normal distributions of other spider families that are less reliant on vision. So this kind of increased variation between eye pairs relating to ecologies, something that again was kind of supported by that original survey. So if we look at an example, so inter-rabdomaric angle versus rabdom length, then again, we can see how it's variation between eye pairs in these kind of different ecological groups. So our web hunters show relatively little functional divergence between eye pairs here. You can actually see the kind of three secondary eye pairs kind of clustered together and a little bit of difference from the principal eyes here. But if you actually then start looking at, for example, free hunters and certainly visual hunters, there's much kind of a greater spread within individual animals across these different axes. Of course, as I said earlier, phylogeny is a really important factor here as well. So in spiders, there's a substantial phylogenetic element to hunting modes. Thanks to a fairly good understanding of spider phylogeny at the family level, we can then use that to reconstruct the illusion of some of these retinal characters in the different eye pairs. So for example, the possible polarisation sensitivity, this perpendicular arrangement of the raptors, we can see that it has occurred multiple times in different spider families and different eye pairs. But it's overwhelmingly appearing after the kind of lots of aerial web-based hunting. So you do see several different origins, but there may well be an ecological correlate there as well. This seems very sensible. Polarisation sensitivity is often used for navigation and all sorts of different art reports, particularly understood in insects. But in some spiders that are free hunters, particularly nephosids and zedarids here, some of those species will actually build themselves a little retreat and they will try and return to that retreat once they're done foraging. So an extra navigational cue seems like a very sensible allocation. Same for if you look at a high resolution, defined as kind of an interceptor angle of less than three degrees. Again, we see multiple origins of this and in many different eye pairs. One thing that's interesting to note, of course, is that they're in different eye pairs from our polarisation sensitivity. Once again, if you have small eyes, they probably can't do two different jobs, so two jobs and two different eye pairs. Even though it's obviously largely restricted to a single clay, so this RTA clay down here is where a lot of visual hunting occurs, there do seem to be multiple origins within that. So obviously, not everything is about retinal parameters. One of the most noticeable things about spiders is the variation in eye size and position. Obviously, these things impact field of view, sensitivity and resolution, and both absolute and relative size do vary substantially. If you kind of just very, very roughly plot out their relative size, you can see quite quickly that our visual hunting groups do have more variation between eyes and within eye types as well. So there's definitely more differential investment. But obviously, position and orientation are also very important to field of view. So basically what space the eye is sampling in particular. We know that spiders have quite different fields of view for different eye pairs. This is some really classic work from my friend, showing that you do see kind of overlap, not only between eyes within eye pairs, but sometimes between eye pairs as well. So what we did to examine this was to take a geometric morphometrics approach. So each eye was given two landmarks at the centre of the inner and outer surfaces and 11 sliding semi landmarks around the edge of the eye. So you can see that this means that you can register them and put them after a process alignment. You can then essentially compare the coordinates of those landmarks in three dimensions between species as though they were multivariate data. So the two landmarks in blue and pink there would be essentially a homologous between species to compare. This basically means that we can then analyze them via PCA to look at relationships in a reduced number of dimensions, but capturing most of the variation in shape. So here they are coloured by hunting mode, first of all. And you can see that there is actually some separation between the visual hunters and the other two groups. There's quite a lot of overlap between our web hunters and our free hunters, which is interesting. And there's less variation in our web hunters as well. And given that they've got a more similar lifestyle, maybe you could extrapolate some meaning from that. And actually looking at a couple of examples of those species, we do have a couple of interesting things coming up. So on the right-hand side, we've got our two visual hunters, which actually ostensibly look like they're shaped quite differently. And our two web hunters at the top left there, which look very similar, but occupy seemingly slightly different parts of space. However, obviously, as I said, phylogeny is a very important part of this as well. So if we superimpose the phylogeny onto our PCA, we can actually see that there may well be some confounding effects of phylogeny here, particularly in our visual hunters. But what you can do is then incorporate the phylogeny into your PCA. So basically, this is just making sure that the phylogeny is mostly explained by the first principal component. So if you look at our second principal component, which should actually relate only to shape, we still see this really nice separation. Between our visual hunters and our non-visual hunters. So now we can be fairly confident that there is probably some real signal here perhaps relating to ecology. So what does that actually mean for our configuration? So if we look at the maxima and minima of different principal components, we can start to unpick what those different components and how they change. So for example, if we look at PC2, so where we saw that kind of nice separation, we can actually see that there's a difference in costar. So if you look at our wolf spider at the bottom right here, you can see that actually three of the eyes are clustered towards the anterior of the head. And in blue, which is our kind of maximum for that principal component, we see these three eyes clustered towards the front. But if we look at our web hunter here, we've got this very classic kind of halo arrangement of the eyes giving a 360-degree field of view around the head with very little overlap. And that's what you can see at the minimum of PC2. You can see that the lines in the center here indicate orientation of the lens. So we can also then apply ancestral state reconstruction to this. Now that we've got the principal components and we have phylogenia as a factor, we can actually project backwards in time and start to look at how these principal components have changed. So then that obviously means we can look at correlations with ecological shifts and start to kind of piece together an idea of what ancestral what spider visual systems might have looked like. So the bottom right here is just the prediction for PC2. So the component we just looked at in the most recent common ancestor of all spiders. And you can see that that does have this kind of distributed nature. And from this we can refine that, as I said, the ancestral state is this kind of distribution of eyes. Actually, the all web spiders have this kind of halo arrangement kind of coincide. But then actually you also see this shift to anterior concentration of eyes in the same plate as you see visual content. So obviously this is correlative. I can't pinpoint it. This is exactly the reason that you see this anterior clustering, but it makes logical sense. And it really, it matches up very well with these kind of shifts that we see in spider ecology evolution as well. So we kind of see two very different approaches then to having many eyes and spiders and obviously depending on the importance of vision there seems to be to obviously equally good strategies to having many eyes. So at the one end of the spectrum we still have our kind of relatively few types with not that much kind of divergence between the secondary eyes and the principal eyes. We see a much more equal size balance, smaller maximum size of the eyes and again this kind of field of view is split equally between the four eye pairs. We do actually see something again to not necessarily assess our lifestyle. We don't have any immobile spiders, but certainly, you know, in more pleasing morphic lineage is you might have a kind of burrow hunting or, you know, sitting in all webs for all believers. We also have kind of more active lifestyles, but visual hunting spiders and those ground hunting spiders. We do see greater divergence between eyes and eye types and more variable size as well as this kind of anterior concentration and resum player anterior space. So how exactly these changes occur. Obviously, this is a huge question and deserves its entire own, its entire own talk. We also have some of the key features of eye configurations and spiders, so the really nice place to start here of course is eye size. It obviously has direct links to resolution and contrast sensitivity, as well as being a good indicator of investments. And it's also frankly much easier to measure than many of the other characters that you might be interested in. So, over the next few slides, I'm actually going to show you some work that was done by my post-op, the reach powder in Gonzalez, looking at how eye sizes patterns and developing spiders of different families and different visual ecologies. So, he's actually been working over the last year and a half, I guess, nearly two years to work with embryos of always different spider species and start to look at what genes might be impacting how their visual systems develop. And as you can see, they actually represent a really nice range of different arrangements and sizes. So we have a good understanding of the genetic factors controlling eye development in your software course. And because we have a probable homology between the principal eyes of spiders and the cell eye of insects and the secondary eyes of spiders and the compound eyes of insects, we can use this as a kind of blueprint to start thinking about what genes might be important. And there's been a small body of work on this before, before we got started. But what we've kind of broadly taken from that is that we do see quite a lot of similarity between, say, Paracetona, which is this model spider with Drosophila. But we also find that, generally speaking, very similar retinal determination genes are probably expressed in the compound eyes and secondary eyes and then the SLI and the principal eyes, which is very neat. One thing that we do see is that, actually, both of those eye primordia are probably surrounded and constrained by wind segments. That may well have quite important roles to play when thinking about size and how it's determined. One of the interesting things that just because it's a vision audience, I know that somebody will ask about it otherwise, is where's PAC-6? You know, why do we not see PAC-6 here as our wonderful master regulator? Many people before me and Luis have looked for PAC-6 in developing spider eyes. In Paracetona, it just isn't there. And actually, in the other species that I just showed you a list of, we're not finding any real evidence of strong PAC-6 expression in any of these eye primordia, which is an interesting spider weirdness. But there was a paper that came out only a month ago or two months ago from Natasha Turetz and her group demonstrating that they found expression of PAC-2 in the areas that you might expect PAC-6 to actually appear instead. So there's a really interesting potential story there about co-option of PAC-2 to do PAC-6's job. But that's an aside. I went to a credit today, but I thought we would be interested to hear it go and read their paper. So one of the other great things about spiders that really gets people quite interested in the genetics and the development is that along with other arachnopulminates, they've actually undergone a whole genome duplication. So they see a lot of the genes that although they're possibly doing the same job as in Drosophila, a lot of them are present in duplicate and the end-resinal determination gene that works. However, although this seemed like a very tantalising opportunity to then sub-functionalise and use that as a tool kit to make your eye configurations very diverse and very crazy, we actually don't see that much difference in copy numbers between any of these genes, between any of our families. So, you know, it's not necessarily about what these genes are doing, and in terms of sequences, they're also not very divergent. So probably isn't down to this whole genome duplication and the abundance of possible determination genes. But that must mean that it's probably about how these genes are expressed. So this project started in, I guess, in August 2020. So looking at depths of lockdown, it's mostly been a COVID project. But it means that Luís and I have spent the last year also collecting spiders and raiding colonies of spiders in our houses, at least at my end, much to the chagra of my husband. But it means that we have been kind of, you know, trying to keep these things alive at home to some extent. And of course, the purpose of this is then to get embryos, these are like very cute jelly baby versions of spiders for in-situ hydrolysations to look at where these genes are expressed. So I'm just going to show you a couple of these different genes and then I realize this is a very busy overwhelming slide. Don't worry, I will pick out what is important. Just a couple of the things that we've noticed from some key genes. So first of all, we're looking at synopsulus, which is one of these kind of great marker genes for looking at where the eye primary are. And if we just look at these three species. So we have pardosa inantata on the left, which is the wolf spider. Narcissa muscosa in the middle, which is a jumping spider. And falcus flangioides on the right-hand side, which is the daddy-gone-leg spider. The one that will sit in the corner ceiling of your bedroom and spin wildly if you bother it. So one of the things that you can see here is that in both our wolf spider and in our jumping spider, we do have different sized primordia, kind of course, this sense for the different eye pairs, and they do broadly reflect adult eye size. What we don't see is the same thing in falcus. I think it's kind of an interesting little comparison. The other thing is that now that we've looked at synopsulus expression in these two species that have very large eyes, something that wasn't previously visible from examinations of paracetodo, which has quite small eyes, is that it also looks like this kind of two distinct areas. So there's this halo of expression, and there's potentially a more kind of concentrated dot here at the ventral side of the eye. So that could be an interesting tidbit and a good lead to follow up on, maybe. We actually see something very similar when you look at eyes absent. So if you actually, again, look at those same three species, we have really nice demonstration of different eye sizes in these two species. But again, falcus has these kind of, they're clearly distinct three different primordia from the secondary eyes, but they're a very similar size to our principal eyes here. When actually in adults, they're much, much larger. Finally, just one more, but I think it's interesting, and I kind of want to hear people's thoughts on it, but it remains somewhat mysterious. We also looked at six threes. This is optics and interest software. This is only expressed in the secondary eye pairs, but I just wanted to draw your attention to this expression pattern in Markissa. So this is one of the cases where we do have two copies, both copies are expressed in the eyes, but they seem to have very different expression patterns, which I think is quite interesting. So you can see that the one copy on the left-hand side here is only a very small concentrated dot, but again does not reflect eye size. But if you compare that with the odd log on the side, the expression patterns of six three point two always look like they wrap around those expression domains of six three one. Again, this particular gene does reflect differences in adult eye size, but its counterpart does not. So this is one I'm keen to follow up on, but would be very interested to hear interpretations of these expression patterns. So if developmental patterning can't explain everything that we're seeing vary in adults, and there might be something else happening during growth, as opposed to during development. So this is some work from Kaylin Chong, who's an undergraduate working in my lab, and she looked at static monetary in a range of different species with different new apologies. And so a lot of trees that if you have a feature that grows a different rate from the rest of the body, so the classic example is the human head, because if it's very strong negative monetary giant headed babies and small headed adults, which often reflects kind of a greater necessity for investment early in life. So Kaylin actually measured some crazy number of specimens, I think more than 1100 specimens from our collections in Oxford, across 36 different species and six different families with variable visual ecology. So she actually just took a carapace with measurement and then diameter measurements of those four eyepairs. And actually, if you if you do have a look at we have a process all these years, I'm just giving a quick overview of this. But if you, for example, compare salticides, jumping spiders and RNAs, which are all weavers, and visual and a non visual family, there's a clear difference in size and distribution. So obviously that's just the height of the slope, but also possibly in growth as well. So the gradient of that slope there. For comparison, there is some other work on ionometry and spiders. So this really nice paper, again, from, I think, from MATE Lab, showed really nicely that you do get negative ionotree in salticit eyes. This was looking at developmental stages or ontogenetic stages, sorry, so different instars across that initial growth. So negative ionotree here makes a lot of sense. Obviously vision is crucial for survival of these animals, so they invest super, super early. What was really interesting that we found in our adults of different sizes, was that actually we found our sometry in all the eye pairs that we looked at in particularly these two salticit species. So this basically means that the slope is not significantly different from one, the eye is just growing at the same rate as the rest of the body. So this is interesting for a couple of reasons, there could be a shift in growth dynamics perhaps, but it's interesting because we were expecting to just see a continuation of this negative ionotree that Nate's group had demonstrated really nicely. What's interesting, we did actually then see that in our non-visual group in the RNA. So here we did find isometry, again, the principal eyes, but the three secondary eye pairs, all showing that kind of negative alimentary growth. So not sure whether to interpret that as, you know, this continuing investment from salticit in these eye pairs as they grow. The positive ionotree is not that common, but it's seen in things like sexual selection characteristics. So it could be that it's just a very important trait they can keep investing as the ion or grows and grows. If you just look at the salticit and you kind of make a comparison across different species, you can also see that there's a clear difference between eye pairs as well. So even though we saw that all four eye pairs exhibit isometry, there's clearly something slightly different happening in the different eye pairs once you look across different species. So there's a really, really tight relationship there between the secondary eyes and the eye size and the principal eyes, but it seems to be much looser once you're looking at the posterior median eyes, which are broadly thought to be probably the structural and not doing very much. If you come back to our falses though, we still don't have a satisfactory answer as to when the size of those secondary eyes is established. So what we actually see here is that the secondary eyes are negatively alimentary again. So this should mean that they have already invested in that eye size and they don't grow any further. So we've looked at what we've seen in our gene expression studies so far because we didn't see this kind of reflection of adult eye size. So either we're missing something, so there could be something happening in those instar phases where the Goethe paper showed that in sultisids. Alternately it could be that there are other genes that determine and pattern eye size in focus that we haven't tried in our institute yet. So if we come kind of background now, I suppose, to our overall proposed spectrum, we kind of wanted to suggest that there was this range of different approaches to having many eyes with a high eye number, a few types and maybe a kind of sessile lifestyle at one end and a lower eye number and larger or more specialized eyes at the other end. And we do see generally that that is quite well represented within the spiders as well. They cover that kind of bite size part of that overall spectrum but those overall patterns kind of follow the same vein and that's removing, you know, some of the variables like broader kind of phylogenetic constraint that's removing eye number from consideration. So they do actually give us hopefully quite a nice closed system that looks like it might be representative of that whole spectrum, which gives us a really nice opportunity then to explore some of the questions that we've set out today. And one of the particularly kind of interesting bits is that the possibility that we're seeing a transition from duplicated systems to parallel systems and some of those secondary eyes there. They all share their developmental origins but we're seeing them try to collect different information despite that kind of shared origin. So there's also the opportunity to then try and add in variation in eye number in future and in the number of eye types. So for example, particularly in this more, please, the morphic part of the tree at the top here, they actually do see quite a lot of variation in some families in eye number. So I've just spoken about families that have eight eyes today. But actually in several different groups, particularly the components are a really interesting family for this reason, is that they have species with eight, six, four, two and zero eyes, which is really interesting. So obviously where you do have species that lack eyes completely, there's usually a very obvious ecological reason. For example, they might inhabit caves, but for the components, you get all these in-between combinations as well, which I think is really, really interesting. So something that I want to kind of do a bit further down the line is whether we then see compensation, for example, for loss of part of the field of view being covered, do we see divergence between the remaining types, particularly when a principal eye is lost. So these families are possibly a really nice new resource for further information on the importance of eye number specifically. So that's, as far as I wanted to take you with the spiders and particularly the overall survey as well, but before I hand back over to George, it hopefully takes some of your questions. So I'm going to shamelessly plug a couple of things that we have going on. So first of all, and for me, most importantly, we're currently hiring. So I'm looking for both a postdoc and a PhD student to start in the next couple of months, the next few months. So if you or anybody, you know what anybody in your lab is looking for a position, please encourage them to check out the website or get in touch with me if they have any questions. Both of these positions will be closing in the next few weeks. But again, do get in touch with me if you have anybody in mind or if you want to know more about you of those. And secondly, the, if you're interested in the kind of broader concepts of these multi-eyed visual systems, there will actually be a book coming out, which has been edited by Elka and Mike as part of the Springer series and vision research. So hopefully that will be coming out at some point in the next year perhaps, but that will be, it's a compilation of work by many, many other people. But if you'll really kind of want to get your teeth into more of these kind of weird and wonderful systems, that'd be a very good place to do it. And that just brings me to my last slide, so to thank everybody who's been involved in this work at every level from collecting specimens and delivering things to working in the group. And of course to thank my funders and to thank you all for your attention as well. Thank you very much, Lauren, for this fantastic talk. The complexity of the visual systems out there is like amusing, captivating, and of course alarming, because if we only focus on model groups, then we miss or misinterpret so much information. So for the time being, I will try to just act as a moderator and convey questions that appear in the chat. I have already posted the Zoom link in case someone already would like to join us. And the first question appearing is from Madine Sarvestani. Do we know whether spider head movements preferentially stabilize gaze on principal eyes or all eyes? That's a great question. So actually one of the really nice things that I didn't mention about spiders is that the retinas have muscles to move them around as well. So actually they wouldn't necessarily need to use head movements for gaze stabilization. They actually have the ability to move the retina around the back of the lens of the eye itself. So I know that looking at gaze while static, a lot of work has been done with eye tracking by a couple of groups who are in the US. While moving, I'm not sure actually. I would assume that there probably is some way of stabilizing the gaze while spiders walk. Anecdotally from watching visual hunters hunt, they tend to stop and watch rather than kind of move and track fray. But that's something that a jumping spider expert would have to weigh in on, I think. Right, and down this topic. So do you think that different spiders use vision more than others for species recognition? Like trying to draw parallels with what mantis shrimp visual complexity conveys as an advantage? Do you think different spiders would rely on a different extent for species recognition in their vision? Absolutely, yeah. So we can certainly see that, they're not the only example, but the jumping spiders are definitely the best example of this, where not only the species recognition, but there are really beautiful studies with here how individuals track different body parts of another individual during, for example, the mating display. So certainly there's ability for not only your own species recognition, but I think also for, there's been some nice work looking at the comparison of silhouettes of possible prey items with other silhouettes. So certainly where the resolution is high enough, I think there is definitely some recognition going on there. Obviously, if you're a web hunting spider, the reliance on vision is very, very low. But we do obviously have trade-off with things like vibration sensitivity. There you do have not necessarily species recognition, but very good recognition of the different signatures of vibrations of different possible prey items as well. So definitely differences across different spider species visual. Right. Thank you very much for that. So next question is from a user named Mathenol. Have there been studies which either blind or inhibit input from specific eyes and look at subsequent behavioral changes? Yes, yeah, absolutely. So again, this has mostly been, but not exclusively in jumping spiders. There was some, there's already very well established work that means that the secondary, sorry, the anterior lateral eyes and the principal eyes, these kind of pointing in the same direction, that covering one set means that you kind of lose that recognition of movement and covering other set reduces the amount of detail that can be seen. So there is some really nice work explicitly demonstrating that, you know, those two iPairs facing the same direction are doing very, very different jobs. Right. And given that you mentioned the jumping spiders. So like, I think there was a paper, maybe like around 10 years ago that they examined the jumping spiders and they found that they have like two photoreceptor layers, one having the image in focus and one out of focus. And this would help with depth perception, like within a single eye. How specific is this to jumping spider? Like this kind of complexity. Is it evident across the spider tree or? So in terms of kind of multi-layered retina, I mean, it's definitely greatest as far as we know in the jumping spider. But in some cramped spiders, for example, in the principal eyes, you do also get a kind of a slightly elongated two-level retina there as well. So there are examples of being elsewhere, but jumping spiders, it's one of those things where jumping spiders are the kind of Olympians and visions. They've received a lot of attention and a lot of behavioral work. They're also the best to get a behavioral reaction out of. There are many spiders that you can't get to, you know, surprise them with a move. They might not react, but they've been a really exceptional model. But certainly from morphology, we can see similar trends in some other groups, but it's not really to the same scale as it is in this autism. Right. And before I convey the next question that appears, I would like to let you know that there were both greeting messages at the beginning and thank you messages at this point. Because you don't have it open, like it's not that we're just the two of us in the void. So the next one appearing, the chat is from my elder Hugo. In Saltisside, sexual dimorphism can be quite evident. Did you consider looking at the differences in eye or vision between males and females? So we actually basically tried to only use mature emails for these structural studies. So absolutely there's, because there's obviously a really important component of sexual communication, particularly in those groups, but possibly also in groups that we don't know about or haven't studied quite as well. We thought the safest thing to do would be to use a stick to just one sex and to just use mature females. So because at least at the moment our focus is on comparing between these families. We tried to keep that consistent, but absolutely there may well be differences that we see between male and females. We haven't looked into that just yet. Right. Thank you very much for that. And the last question appearing in the chat and this would be the last that I would ask you to address indirectly. People are more than welcome to join us in the Zoom room for which the link I have reposted. So the last one appearing is from Sam Budov. Thank you. Super interesting talk with respect to the topographic asymmetries. Are there retinal specializations like streaks or area centralis? What are the topographies like between eyes in a single species? So the kind of high resolution reconstructions of the retinal mosaic are still ongoing. So we've only got a couple of species for this so far. We are definitely seeing at least in the species that we've got. So these crab spiders that we're looking at that does seem to be a kind of horizontal streak along the middle of the higher resolution reduced skew as well. But one thing we're seeing is also kind of sometimes some kind of almost a disruption like a vertical line down the center of the retina. Whether this is, it could be a structural artifact whether that's where the vitroceptors are then being kind of carried through the torpedo is not entirely evident yet, but there are definitely structural features in the retina that keep coming up. So this horizontal streak is definitely one of the individual hunters. Right. And before I terminate the broadcast down this path. So you saw like for example the area of high density for photoreceptors or you know areas that the raptomers are of different size. And do you think like this would reflect also what happens like for the downstream layers? That's a great question. That's something I can't give you a satisfactory answer for right now. I mean, there's some really nice work by Sky Long and some of her colleagues on the visual neuro pills and kind of how the morphology of the visual neuro pills varies between groups with different reliance on vision and it's a really quite staggering difference. So it's the point of having more or fewer visual neuro pills in different families which is pretty, you know, that's a pretty large scale evolutionary change to your brain structure. So I'm certain that there'll be a reflection of more detailed points as well. Absolutely. Right. So thank you very much once again Lauren for this fantastic talk and so many organisms and like the complexities like outwardly. So I would like to thank the audience for being here and I would be terminating the broadcast. The zoom room link is still visible so in case you would like to keep track or participate in the ongoing discussion please make sure to click on it. Thank you very much. Thank you very much. And we are officially offline and people are already here.