4 ms·
Weirdly, echinoderms are considered part of the Bilateria clade. Apparently they're bilateral as juveniles and only become radially symmetric as adults (https:
by mishac 7y ago
Weirdly, echinoderms are considered part of the Bilateria clade.
Apparently they're bilateral as juveniles and only become radially symmetric as adults (https://en.wikipedia.org/wiki/Bilateria https://en.wikipedia.org/wiki/Bilateria)
- elliekelly 7y agoWhoa, it does actually look like a little biped flubber: http://science-at-home.org/wp-content/uploads/2009/12/starfish_larva.jpg http://science-at-home.org/wp-content/uploads/2009/12/starfi...
- cjensen 7y agoYep. If you look carefully at a most starfish, you can see that they are bilaterally symmetric. For example, when there are five legs, if you mentally halve the animal along a leg, only one of the five legs results in both sides matching.
- gowld 7y agoThat still undermines the articles thesis and that an odd leg can't be bilateral.
- kittiepryde 7y agoI have one head and four appendages (two for each side, but only one head bilateral down the middle). I don't see why they couldn't have a leg, bilateral down the middle ( like a head?)
- fla 7y agoOr a tail
- smackay 7y agoAnyone know if there is "handedness" in tails, particularly in monkeys where they use their tails while climbing. Do individuals always curl their tails clockwise or anticlockwise around a branch?
- e12e 7y agoWell, technically you have a tail too. I suppose a better description would be a spine, stunted in one end (tailbone), extended at the top (head), with two set of limb pairs (arms, legs).
- matt-attack 7y agoWell said and excellent point.
- eternalny1 7y agoHence the "almost all".
- perl4ever 7y agoWell, if I were a starfish, I would take issue with that dismissive phrase. They are members of a large, and, I assume, proud phylum. "Echinodermata [is the] second-largest grouping of deuterostomes (a superphylum), after the chordates...Echinoderms are also the largest phylum that has no freshwater or terrestrial (land-based) representatives." https://en.wikipedia.org/wiki/Echinoderm https://en.wikipedia.org/wiki/Echinoderm
- perl4ever 7y agoWell, that's exactly what proves the point that you could evolve three legged animals from bilaterally symmetric ones.