ANT 201: Intro To Evolutionary Theory

Evolution

Change in trait frequencies over time

*specifically allele frequencies

ex: fly changing eye color from one gene to the next

At it’s core Evolution is a

genetic process

Microevolution

Evolution on a small scale, such as changes within a population.

Macroevolution

Evolution on a large scale, such as the creation of new species.

Evolutionary theory

An explanation for natural phenomena, thoroughly tested and supported

Evolutionary Theory focuses on

change through time + the diversification of life

Evolutionary Fact

An observable phenomenon

Aristotle believed

Great Chain of Being and the fixity of species

*Aristotle is a fixed speaker across subjects

St. Augustine believed

Creation of Earth + “Types of life” and that species didn’t change

*S.t is a title that affects the way you live—> a type of lifestyle and it doesn’t change

Ibn Khaldun believed

types could change and propose that humans evolved from primates and that humans are the highest form of life

*Ibn —> changing letters, classy name—> high title

Thomas Malthus believed

Humans are the highest but argued that resources affect population growth

—> leading to competition and potential extinction.

*Malthus/“Mouth” ..”mouths to feed”—> competition

Georges Cuvier

Used anatomy to study extinction and contributed to the field of paleontology

• famine, floods etc.

*Cuvier: cut/carve inside—> anatomy

Charles Lyell

Introduced the concept of uniformitarianism, which suggests that geological processes take time (earth was old enough)

*ll at the end is parallel —> uniformity

Transmutation Hypothesis

Living species are derived from older, similar species

Jean-Baptiste Lamarck: Inheritance of Acquired Characteristics

changes you made individually would be passed on as well as the use or disuse would affect structures and heritability of traits

Evolution via Natural Selection

• Variation exists and is heritable

• Competition for limited resources

• Differential survival and reproduction (fitness)

• Beneficial traits increase in frequency

*We’re all different and we’re all competing to be the best, we all try different techniques to survive life, and the best of us get to pass it down and increase amount of people with that trait

Evolution occurs at both a ___ and ___ level

Population and Species level

Population

A group of individuals from the same species

True or False:

Individuals can’t evolve during their lifetime

True

True or False:

Natural Selection leads to the development of new traits

False

mutation does

True or False:

Creation and Evolution can be inherently compatible

True

Species

A group of organisms that can interbreed and produce fertile offspring.

Ancestral Traits vs Derived Traits

Ancestral traits are shared with a common ancestor, while derived traits are unique to a particular species

Social Darwinism

Incorrect belief that certain conditions, such as poverty or being in jail, are due to genetic disposition

(you’re in poverty because you’re genetically disposed to be in that setting)

*WRONG

Stabilizing Selection

Selection against extremes, favoring the average

Directional Selection

Selection against one extreme, favoring the other extreme [one direction]

• an extreme phenotype is favored over other phenotypes, causing the allele frequency to shift over time in the direction of that phenotype

Ex: moth colors pre + post-industrial revolution

Diversifying (disrupting) Selection

Selection for both extremes of a trait

• the variance of the trait increases and the population is divided into two distinct groups

Ex: squirrels with either no tail or long tails

Membrane

Regulates the passage of molecules

• separates and protects the interior of a cell from the outside environment

*Membrane “member” —> you need to be a member to get in

Cytoplasm

Jelly-like matrix that holds organelles

Nucleus

Contains the cell's DNA

Mitochondrion

Produces adenosine triphosphate (ATP)

*ATP.. “at this point” you should know that it does more than act as the powerhouse of a cell

Endoplasmic Reticulum

Involved in the synthesis of proteins, lipids, and carbohydrates

*PLC

Ribosomes

Site of protein synthesis

Centrioles

Assist in cell division

*Center ..where the action happens

Procaryotes

Single-celled organisms

Eukaryotic

Single or multi-celled organisms

*EUK- “Unique” …can do multiple things

What makes up a nucleotide?

Sugar + Phosphate + Nitrogen Base

What are the 4 Nitrogen Bases?

Adenine-Thymine, Cytosine-Guanine

[AT] [CG]

• single strand of DNA

Two Strands of DNA are considered

complimentary and anti-parrellel

*CAP

DNA Replication

Initiation: enzymes separate hydrogen bonds that hold complementary strands

Elongation: Enzyme reads the order and pairs complementary bases

Termination: Completion + creation of nucleotide

*Rip a toxic couple apart, match them to better people, create a new and better couple

True or False

Nuclear DNA is passed down by both parents

True

True or False

DNA is only inherited from the female

True

RNA

• single-stranded

• lacks thymine + replaced with uracil

• Important for protein synthesis.

What does RNA Preliminary do?

Comes in and reads one strand for protein and brings its complimentary bases

Intron

some code is cut out to connect exons

*go in to take it out

Alternative Splicing

different combinations of exons lead to different proteins

Translation

mRNA goes to ribosome to read codons (3 based sequences)

• TRNA has opposite codons

• amino acids link to create a peptide chain

Chromosomes

DNA -> Chromatin -> Chromosome

Chromatin

tightly coiled

-in … inside for coverage (tight coil)

Euchromatin

loosely coiled

Chromosome Structure

Center: centromere

Ends: Telomere

Arms: shirts (p) + Long (q)

Genes

Coding sections of DNA are found on a chromosome

Alleles

alternate forms of a gene

• you don’t have good gene, you have good alleles

Locus

part of a chromosome where a specific gene is located

*Loco—> location

Genome

the entire set of dNA in a cell

Somatic Cells

any cell of a living organism other than the reproductive cells

• responsible for organ. growth + development

Humans have __ chromosmes

46 (23 homologus pairs)

• 22 autosomal, 1 sex

Trysomine 21 leads to

down syndrome

Genotype

combination of alleles present (inside)

• homozygous

• heterozygous

Phenotype

physical trait expressed based on the genotype

• hair color

Gametes

a mature haploid male or female germ that unites w/ the other of the opposite sex to create a zygote

Haploid (one of each type of chromosome).

Mitosis

results in two identical diploid daughter cells

Diploid cell —> DNA replication —> chromosomes line up in the center —> sister chrom.pulled

Meiosis

results in four haploid daughter cells/gametes

• Involves crossing over

• Dividing a cell into 2 cells

• Final steps happens ONLY if fertilization occurs and ¼ is taken

Which of the two cell divisions is important from an evolutionary standpoint and why

Meiosis

A: involved in the reproductive process