Word & Picture Definition

Acquired characteristics

The ability to play a sport or read music are thing that you learn over a lifetime and are NOT traits that can be passed

on via heredity. We call traits like these

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Adaptation

This is what we call physical or behavioral changes in a population over

several generations to be better matched to the conditions of the local environment. This will always happen at the population level and NOT at the

individual level.

Adaptive Radiation

In a brief period of time, a small number of species diversify into a large number

of species, able to live in a wide diversity of habitats. This can occur due to Colonizing events, Mass extinction

events or Mutations to specific genes.

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Word & Picture Definition

Artificial Selection

Breeding with a specific purpose or goal in mind. This is how we have

derived all of our breeds of domesticated crops and animals.

Individuals will be more closely related to those living nearby even if they are living in dissimilar conditions than they will be to individuals living in identical

conditions in a different part of the planet.

Ecological races

These will develop within a species when reproductive isolation allows

genetic divergence and adaptation to local conditions but not enough change

to prevent reproduction when the species members are reunited.

Biog

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Word & Picture Definition

Gene flowWhen individuals move from population A to population B they take their genes

with them. This changes the allelic frequency of one or both

of the populations.

Genetic drift

Reproductive fitness is not a factor for this mechanism of evolution.

Bottleneck:When a catastrophic event removes random members of the population and changes the allelic frequency.

Founder effect:When by random chance a group with unique set of traits starts a new population with an allelic frequency different than the parent population.

Genetic Divergence

When species are reproductively isolated they will accumulate different mutations. The longer the two species are separated the more changes will be detectable in the genome. This division

between the species genes is called

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Word & Picture Definition

Gradualism

This describes speciation as the slow accumulation of changes (mutations) that would be expected under normal

selection conditions.

These are similar structures found within different animal groups that

demonstrate common ancestry. The same bones that were built from the

same genes but with changes in function and size.

Same bone pattern, new use.

When we have variation, heritability and differential reproductive success this mechanism of evolution will occur.

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Word & Picture Definition

Non-Random MatingWhen one individual controls a territory

and passes on more genes than other males or females. This can also happen

if the population is limited and there aren’t options for reproductive partners.

Punctuated equilibrium

This describes speciation as a fast (geologically speaking) accumulation of changes (mutations) that would be

expected under unique conditions.

Unique conditions: Colonizing events Mass extinction event (Unit 11)

Evolutionary innovations (Unit 14)

Reproductive isolation

This describes the types of situations that could keep populations apart and

unable to have healthy offspring.

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Word & Picture Definition

Selection Pressure

Any situation that reduces reproductive success in a portion of a population. This could be a predator, the temperature, moisture, pH, etc.

SpeciationThe end result of reproductive isolation,

genetic divergence and adaptation to different environments. For this process

to be complete, the two populations must now be unable to reproduce and

have healthy/fertile offspring.

This describes a fossil that shows an intermediate form between two

established groups. The example shown is of Tiktaalik roseae. Tiktaalik

demonstrates a form between ancestral fish and amphibians. Tiktaalik would

have lived full time in the water but had features that allowed for a more

terrestrial lifestyle in future generations.

Transitional fossil

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Word & Picture Definition

This describes a structure that is still made but has no current functional use.

The example shown is the yolk sac for humans. We are placental mammals and do not need to produce yolk as we get our nourishment from our mothers.

Our yolk sac genes still work to produce a yolk sac but our genes for the yolk itself have been broken over

time by mutation. We carry these broken genes as the genetic baggage of our descent with modification.

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