The paradox behind the pattern of rapid adaptive radiation ...
Adaptive Radiation
description
Transcript of Adaptive Radiation
![Page 1: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/1.jpg)
Adaptive Radiation
![Page 2: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/2.jpg)
Cambrian Explosion
![Page 3: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/3.jpg)
Cambrian Explosion
![Page 4: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/4.jpg)
Fig. 25-10
Spon
ges
LateProterozoiceon
EarlyPaleozoicera(Cambrianperiod)
Cnid
aria
ns
Anne
lids
Brac
hiop
ods
Echi
node
rms
Chor
date
s
Mill
ions
of y
ears
ago
500
542
Arth
ropo
ds
Mol
lusc
s
![Page 5: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/5.jpg)
![Page 6: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/6.jpg)
![Page 7: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/7.jpg)
![Page 8: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/8.jpg)
![Page 9: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/9.jpg)
Fig. 25-18
Close North American relative,the tarweed Carlquistia muirii
Argyroxiphium sandwicense
Dubautia linearisDubautia scabra
Dubautia waialealae
Dubautia laxa
HAWAII0.4
millionyears
OAHU3.7
millionyears
KAUAI5.1
millionyears
1.3millionyears
MOLOKAIMAUI
LANAI
![Page 10: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/10.jpg)
Dawkins on Hawaiian Drosophila
Studying Hawaiian Drosophila
![Page 11: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/11.jpg)
Melawi eye biter
Scale-eatingcichlid
![Page 12: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/12.jpg)
Placental and marsupial mammals radiated soon after dinosaur extinction,AND after many other mammal lineages also went extinct (see next slide)
![Page 13: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/13.jpg)
![Page 14: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/14.jpg)
Radiation due to key character evolution?
![Page 15: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/15.jpg)
![Page 16: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/16.jpg)
Russell 1968
![Page 17: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/17.jpg)
4 genera appeared over a 2 my period
Pappogeomys, Cratogeomys, and Orthogeomys diverged over 800,000 years
Molecular data also support a relatively rapid radiation…
![Page 18: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/18.jpg)
From Korth 1994Tertiary Record of Rodents of North America
•The fossil record indicates rapid radiation leading to modern pocket gopher genera in the Blancan•Radiation corresponds with increase in hypsodonty and expansion of grassland
![Page 19: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/19.jpg)
Maybe expansion of Blancan grasslands was responsible for pocket gopher radiation?
![Page 20: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/20.jpg)
Replicated sister-group comparisons:
allow a more refined approach to assessing “key characters” as causes of adaptive radiations
Both clades of herbivorous insects are more taxonomically diverse than their sister groupsThis pattern was seen in 11 of 13 sister group comparisons of herbivorous vs. other
![Page 21: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/21.jpg)
Example radiation: Land plants are a monophyletic group that has evolved fit many ecological niches
![Page 22: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/22.jpg)
Waxy cuticle prevents water loss
Stomata allow gas exchangethrough the waxy cuticle
![Page 23: Adaptive Radiation](https://reader035.fdocuments.in/reader035/viewer/2022062520/56816583550346895dd82c3f/html5/thumbnails/23.jpg)