Darwinism and Evolution

Descent with modification

Darwin's term for evolution, the accumulation of changes coming from a single ancestor

Fitness

A measurement of how many offspring an organism leaves

Unity of life

Different species on Earth all share similar life features

Population

All of the organisms in a given environment that are capable of reproducing with one another

Lamarckian Evolution

The various traits an organism develops over its life span will be passed to its offspring

Darwinian Evolution

Mutations in DNA lead to differences in phenotype, some of which can make a certain organism better at surviving and reproducing

Lamarck

An early evolutionary thinker back in the 1800s, had the right concept but the wrong specifics

Cuvier

Studied evolution through fossils, if the Earth is changing and species adapt to live on Earth, the species must also be changing

Common ancestor

A shared ancestor among various species, from which they have evolved past but share a similar lineage

Phylogeny

The study of evolution through the use of diagrams that look like trees called cladograms

Extinct

A species that is no longer living

Extant

A species that is still living

Genetic drift

Describes the change in population because of a random event, common with small populations

Gene flow

Describes a change in allele frequency due to the entrance or departure of various individuals from the gene pool

Artificial selection

Selective breeding, done with dogs

Reproductive success

A measure of fitness, how many offspring an individual leaves

Epigenetics

The turning on/off of specific genes within a genome, can be passed from parent to offspring

Evolutionary adaptation

An inherited trait that enhances an organism's ability to survive and reproduce in a particular environment

Comparative anatomy

The process of comparing two organisms based on their number of shared characteristics

Homologous structures

Derived from a common ancestor, same/similar feature in two branched species

Analogous structures

Similar structures, though evolved separately, independent of each other

Convergent evolution

Occurs when there are similar environmental pressures resulting in analogous structures

Macroevolution

Change that occurs above the species level, results in speciation

Microevolution

Adaptations that evolve within a population as a result of allelic frequency change

"Modern Synthesis"

Defines evolution as the change of genetic make-up of a population over time

Gene pool

All of the alleles for every single loci for all individuals in a population that reproduces

Bottle neck effect

When a large disaster occurs, leaving a population significantly smaller

Founder effect

When a small group of a population splits off and creates a new population

Directional selection

When natural selection changes the average allele frequency to something else

Disruptive selection

When natural selection shifts the mean to two separate opposite ends

Stabilizing selection

When natural selection shifts more towards the mean allelic frequency

Sexual selection

When a particular trait is only adaptive in terms of attracting mates

Neutral variation

Describes genetic variation that is preserved, things aren't selected for or against anything

Diploidy

There are two genes for a trait with one being recessive

Heterozygote advantage

When an organism has an advantage due to being heterozygous

Frequency dependent selection

When a particular allele not being common is a good thing

Balancing selection

Natural selection maintaining two or more phenotypic forms

Mutagens

Things that cause mutation in DNA

Darwinism

The term Darwin used rather than evolution

Descent

shared ancestry, resulting in shared characteristics

Modification

accumulation of differences

Life changes, life is not immutable, things survive due to their fitness quality

Within a population variation naturally occurs, nature selects them with various factors from the environment

Fit between organism and environment, life adapts to biotic and abiotic factors

Share characteristics between different animals (unity of life)

Diversity of life, despite differences

Lamarck was an early thinker, but had the incorrect idea/concept of evolution

Cuvier studied fossils to study change over time

Galapagos Island/Finches

Different species had beaks adapted for different food sources

Current species descended from ancestral species (common ancestor)

Natural selection is the mechanism for species modification

Evolution acts on the mutations already present

Sickle Cell/Malaria

Sickle cell provides partial immunity to malaria

Mutations happen by random