Zoology Chapter 6- Evolution

every feature/form of life

what is the product of evolution

evolution (darwinism)

Change in characteristics of a
population that occurs over the course of genera

Darwin theory 1

Living world is always changing and
changes are passed on through heredity.

darwin theory 2

All life has descended from one ancestor

phylogeny

Life’s history is depicted as a branching tree

LUCA

last universal common ancestor

Evidence for common descent

DNA, genetic code, transcription, translation, ATP, shared genes

Homology

similarity attributable to common origin, i.e.,
similarities between (groups of) organisms are explained by a
shared common ancestor who passed on the trait

Homologies

Shared traits indicate evolutionary
relationships between organisms

Morphological homologies

similarites between physical/structural form of animal

Developmental homologies

Similarities of embryo development are due to
common ancestry.

Sequence homology

Shared sequences of nucleotides (DNA,RNA) or
amino acids (protein) due to shared ancestry

Convergence

Evolution of similar structures in
unrelated organisms with similar lifestyle

theory 3 Darwin

multiplication over time

Gradualism

Phenotypic changes occur
slowly and gradually, eventually producing new
species

punctuated equilibrium

change happens
rapidly, and periods of stability can be observed
between periods of sudden change.
 Evidence for both in fossil record

Microevolution

changes in allele frequencies that
lead to different traits within a population over time

Macroevolution

changes that lead to new species
or taxa over time.

Natural Selection

Explains how organisms evolved from a common
ancestor to become the great variety that can be observed today.

natural selection results

traits related to
increased survival and reproduction

Genetic/phenotypic variation generated…

as the result of mutations, genetic recombination, gene
shuffling, etc

Sorting

Survival of different traits

Neo-Darwinism

connects genetics with theory of
evolution

Evolution

change in allele frequency in a population overtime

Evolutionary forces

selection (asexual/sexual), genetic drift, gene flow, mutations

fitness

individual’s ability to propagate(reproduce) its genes