15.3 Flashcards
What is homologous?
similar features that originated in a shared ancestor. Derice from the same structure in the embryo. Can result from modifications that change an original feature to two differen types i.e wing and arm.
It just means that they share a common ancestor
What is analogous?
serve identical functions, and they look somewhat alike. they have very different embryological development, and may be very different in internal anatomy.
What is vestigial?
Features that were useful to an antcestor, but are not useful to the modern organism that has them.
What is coevolution?
the change of two or more species in close association with eachother
What is convergent evolution?
when organisms appear to be very similar but are not closely related at all. Occurs when the environment selects similar phenotypes eveb when the ancestral types were quite different from eachother
What is divergent evolution?
two or more related populations or species become more and more dissimilar; nearly always a response to differing habitats, and can ultimetely result in a new species
What is adaptive radiation?
many related species evolve from a single ancesral species
What is artificial selection?
the process of divergence is sped up artificially, like in the breeding of dogs. Sped up beyond what could have occured in nature naturally.
Are the mouthparts of an adult horsefly and a mosquite homologous or analogous? Why?
homologous becasue they do not serve identical functions.
Are the wings of a bird and the wings of a bee homologous or analogous? Why?
Analogous because they serve identical functions
What does the fact that the hemoglobin or humans and gorillas is nearly identical suggest?
It suggests that a very short amount of time (several million years I’m guessing) has passed since a common ancestor lived.
Are vestigial structures acted on by natural selection?
yes because as we adapt and don’t need them/ don’t help with reproduction we don’t use them and they stop growing fully.
