GENBIO 002: Genetic Drift, Speciation, Evolutionary Thoughts

Genetic Drift

Genetic Drift

change in allele frequencies in a population from generation to generation that occurs due to chance (randomness) events.

Fixation

refers to the elimination of the allele

small populations

Where is genetic drift stronger, small or big populations?

Bottleneck effect

happens when the size of the population is severely reduced.

Bottleneck effect

Type of genetic drift where natural disasters decimate a population.

Founder effect

occurs when a small group in a population splinters off from the original population and forms a new one.

Founders

Those who decided to inhabit the island will be considered ________?

Retinitis pigmentosa

is a relatively rare disorder where the cells in the eye are lost or break down resulting in loss of sight.

Ellis-van Creveld Syndrom

is a rare disorder that also is characterized by dwarfism and sometimes congenital heart defects.

Speciation

the evolutionary process by which populations evolve to become distinct species

Speciation

it is the formation of new lineages

Phylogeny

it is the study of relationships among different groups of organisms and their evolutionary development.

Phylogenetic tree

it is a diagram that represents evolutionary relationships among organisms.

phylogenetic tree

it reflects how species or other groups evolved from a series of common ancestors

Cladogram

it is a hypothetical picture of the actual evolutionary history of the organisms.

Cladogram

It is the subdivision of living organisms into groups based on their attributes.

Phylogenetic Trees

it is an actual presentation of the evolutionary of the organisms

Phylogenetic trees

It is more specifically attempting to reconstruct the order and possibly the timing of speciation events

the further away, the more distantly related.

In phylogenetic trees, the closer to lines are to each other, the more closely related the species.

Allopatric speciation

Occurs when there is an imbalance of gene flow between two population due to a physical barrier

Sympatric Speciation

Occurs when there is an overlapping range of the two diverging species within a region or locality

isolation

It is when organisms of the same species are separated and happens when there is something between the organisms that they can't cross.

Allopatric and Sympatric speciation

Two modes of speciation

Geographic, Temporal, Behavioral Isolation

Types of isolation

Lamarckism/Lamarck’s Theory

this theory states that organisms change through the use and disuse of certain body parts, and those acquired characteristics get passed on to future generations.

Jean Baptiste Lamarck

founder of Lamarckism/Lamarck’s Theory

Inheritance of Acquired Traits

what is the main idea of Lamarckism/Lamarck’s Theory

Charles Darwin and Alfred Wallace

founder of Darwinism/Darwin-Wallace Theory

Darwinism/Darwin-Wallace Theory

theory that states that natural selection as a mechanism of evolution

Modern Synthesis Theory

fusion between Theory of Inheritance and Darwin’s Natural Selection

Population Genetics

basis for inheritance including genetic variation, natural selection and Mendelian inheritance

Modern Synthesis Theory

This theory recognizes several different possible mechanisms of evolution

Darwinism

this theory only believes in natural selection as the basis of evolution

Genes

characteristics passed down from parent from parents to offspring

Modern synthesis theory

This theory argues that characteristics are passed down from parent to offspring on the parts of DNA called genes.

Modern Synthesis Theory

this theory hypothesizes that speciation is most likely due to the gradual accumulation of mutations in the gene level

Fossils

are body parts of living organisms that are buried for a long period of time.

1. Paleontology/Fossil Records

2. Geographical Distribution

3. Comparative Anatomy

4. Comparative Embryology

5. Biochemistry

Evidences of evolution

Carbon Dating

a way to identify age of fossils

Geographical Distribution

It is believed that the world is consisting of a large mass of continent called Pangaea

Pangaea

a large mass of continent or supercontinent is called

Geographical Distribution

there are fossil records and species of the same origins that can be found in places that were believed once together

Comparative Anatomy

the comparative study of the body structures of different species of animals in order to understand the adaptive changes they have undergone in the course of evolution from common ancestors.

Homologous Structure

same structures; different function

Analogous structure

different structure; same function

Vestigial structures

structure of animals that disappear or deteriorate over a period of time due to adaptation

Comparative Biochemistry

the most persuasive evidence that all organisms evolved from a common ancestor

Comparative embryology

The early development of most vertebrate embryos are alike. However, in later stages, the similarities are lost

1. the nucleic acids in almost all organisms have the same genetic code

2. the metabolic pathways of physiological processes like respiration is very similar

3. the universal energy used is ATP

Comparative biochemistry revealed that: