Evolution Business Flashcards
Whats the big, big Hypothesis?
All life on this planet evolved from a common ancestor in the distant past.
Fossils… predictions etc.
Fossils deep in the record should look less like what we have now than new fossils. There should be progression. The ages should match the depths. There should be extinct stuff and transitional stuff.
Homologous Traits… predictions etc.
Homologous traits are characteristics shared between species because of common ancestry. They share the same structure, genetics, or embryonic structure as the common ancestor. This includes Phenotypic homologies, genetic homologies.
Natural Selection
Heritable traits that increase the capability of an individual to survive and reproduce tend to become more common in a population across generations. Not for the good of the species, just what happens when good guys get the girls.
Has anyone ever done natural selection?
With flies. Also E. coli. Observed in canaries.
Sexual Selection
A form of natural selection that accounts for elaborated traits and behaviors that are sexually dimorphic. Occurs when one sex is “choosy”/limiting. Tends to be when one sex invests more in the offspring. The competition will be fierce and specialized.
Anisogamy
“sexual reproduction by the fusion of dissimilar gametes.” result of selection… end up with expensive eggs and cheap sperm.
Benefits of female choice:
Direct= increased nutrition, paternal care (nupital gifts) Indirect= genetically superior mates (fast fish, mobile peacocks).
Are humans sexually dimorphic?
Guys are taller, riskier, kill people more, women want masculine men.
How does homology give proof that everything evolved from one common ancestor?
Shared fundamental chemistry(DNA, RNA, Proteins, Lipids), shared metabolic pathways, nearly universal genetic code, shared genes.
How does the fossil record show that all life evolved from a common ancestor?
(1) One can see the whole progression (2) the stuff closer to us in time and geology looks more like us that the stuff that is older (3) absolute ages match the progression that we are seeing.
If there is one sex that invests more in the production of each offspring…
then the large investment sex will generally have fewer potential reproductive opportunities, so they will be choosier.
Why does sexual selection lead to ridiculous stuff?
Because when the limiting sex is very limiting then that is the main selection pressure.
Vestigiality
is the retention during the process of evolution of genetically determined structures or attributes that have lost some or all of their ancestral function in a given species. Shows evolution because the trait evolved, also shows evolution because the trait looses value and is phased out.
