BIOL 3620, Kyle Summers ECU, Exam 1

Evolution of antibiotic resistance

- work as agents of selection

- evolves quickly and reliably

Phylogenetics

Can use phylogeny or DNA sequencing to determine relationship

Comparative Analysis

Comparing phylogeny to look for convergent evolution

Current Human Era

Anthropocene

Plato

Typological thinking

Aristotle

Scala naturae "ladder of life"

Carl Linnaeus

1707-1778, father of modern taxonomy

Nicholas Steno

First to recognize fossils were remains of organisms

Georges Cuvier

Fossil are remains of extinct species

Georges Buffon

Ancient earth, gradual change of living forms

James Hutton

Slow changes could give rise to geological features given enough time

William Smith

Specific sets of fossils characteristic of specific geological formations

Charles Lyell

The principles of geology, doctrine of uniformitaruanism

Jean-Baptiste Lamarck

inheritance of acquired characteristics

Alfred Russel Wallace

Developed similar conclusions as Darwin and came forward with them before Darwin could

artificial selection

Humans selected traits

4 requirements for natural selection

genetic variation, heritability, overproduction, reproductive advantage

Trade-offs

The development of on trait at the consequence of another

Why can't large organisms have small legs?

Weight increases by volume (m^3) while support strength only increases by cross sectional area (m^2)

Life history

Traits that affect an organism's schedule of reproduction and survival.

Guppy life history experimental tests

- trade offs and constraints

- egg and clutch size

- reproductive maturity

- energy allocation; growth versus survival

Who conducted the guppy life history experiment?

David Resonick

Outcome of lowland environment

Early maturation, large number of offspring

Outcome of highland environment

Late maturation, smaller number of large offspring

Adaptation

Can refer to process or outcome

Units of selection

Replicators and vehicles (gene)

Hamilton's rule

when C < r x B

C = cost to the altruistic party

r = genetic relatedness

B = fitness benefit to recipient of altuism

levels of selection

Phenotypic level at which the effect of a gene is manifest

Kin selection

Natural selection of genes for social action via the sharing of these genes between the performer of the action and its relatives

Three properties of Eusociality

- overlap of generations

- cooperative rearing of young

- non-reducing worker castes

Haplodiploidy

- males are haploid, females are diploid

- sisters should prefer to help raise sisters because they are more related than their daughters

Species that engage in fortress defense

Termites, aphids, thrips

Species that contain life insurers

Ants, bees, wasps

Group selection

Groups consisting of individuals possessing the trait become extinct at a lower rate, and/or produce more descendant groups

What is a critique of group selection?

Groups that consist of altruists are at risk of invasion by selfish individuals

David Lack

Trade offs between offspring number and quality

George Williams

Trade offs between reproducing now and later

What are the main theories for the origins of life?

- primordial soup

- seeds from space

- chemoautotrophy

How old is earth?

4.5-4.6 billion years old

Darwin speculated that life may have originated...

In a small pond

Primordial soup hypothesis

I've originated from simple inorganic molecules

Panspermia hypothesis

microbes from space traveled on meteorites to Earth

Chemoautotrophic hypothesis

Proposes that life originated at a deep-sea hydrothermal vents, where sulfur was abundant.

Miller-Urey Experiment

Found that amino acids can be synthesized under abiotic conditions similar to life on early earth

What is a protocell?

Potential cell precursors made from rapidly forming lipid membranes

Hypercycle

an abstract model of organization of self-replicating molecules connected in a cyclic, autocatalytic manner; happens more easily when enclosed in a membrane

RNA world hypothesis

hypothesis that RNA served as the genetic information of early life

What is a ribozyme?

RNA molecules that can catalyze reactions

What does LUCA stand for?

Last Universal Common Ancestor

What is virulence?

Potential of a pathogen to kill its host

Coincidental evolution

virulence is not a target of selection itself, but an accidental by-product of selection on other traits.

Short-sighted evolution

Success is halted by death in population

Trade-off in viruses

Competition with host must increase or decrease inversely with transmission to new hosts

Vaccination can promote the evolution of virulence by...

- protecting hosts and hence virulent strains

- increasing in-host competitive advantage

Transmission rate hypothesis

If opportunities for transmission are rare, then parasites must preserve their hosts. If opportunities are common then virulence increases.

Vector born parasites are predicted to be...

More virulent

John Snow and the Broad St pump

- proposed that cholera was an infectious agent

- map of pumps and cholera incidence

- was able to show that cholera had originated at the broad st pump

Virulence factors

- tradeoff

- horizontal versus vertical transmission

- competition

- specialization

- history of specific interaction

Major evolutionary transitions

1. Replicating molecules - populations of molecules in compartments

2. Independent replicators - chromosomes

3. RNA as a gene and enzyme - DNA and protein

4. Prokaryotes - Eukaryotes

5. Asexual clones - sexual populations

6. Protists - animals, plants, fungi

7. Solitary individuals - societies

8. Sociality- Eusociality

9. Primate societies - human societies

Evolution of individuality

Social group -> stable social group -> integrated collective

Major transitions often include...

- loss of individual reproduction

- higher level groupings

- changes in information acquisition, processing, transmission and storage

Segregation disorder

Alleles can destroy other gametes

Sd

Driving allele (poison)

Sd+

Normal allele

Rspi

Responder - insensitive (antidote)

Factors that promote cooperation

- genetic similarity

- synergy (principle of division of labor)

- central control (suppression of selfish elements allows cooperation)

Egalitarian/aggregative

Different, coming together

Fraternal/clonal

Same, staying together

Green beard

Single genetic variant (allele) that advertises its own presence with a phenotypic marker

Volvocine aglae

Recent transitions to multicellularity - some species unicellular, some live in groups without specialized somatic and germ cells, some do. - RegA gene

Richard Michod

some gene regulates distinction between somatic and germ cell

Vigilance and prey escape

More animals generally means better chance at survival

Costs of group living

- competition for resources

- exposure to cheating/exploitation

- exposure to parasites

Reciprocity

X undergoes a significant cost to benefit Y. Y in turn provides a benefit back to X.

Enforcement

X punishes Y if Y does not cooperate, making cooperation Y's best option

Byproduct mutualism

X benefits Y as an automatic consequence of X's actions

Factors promoting cooperation and preventing cancer

- control proliferation

- control apoptosis

- control resource allocation

- control cell differentiation

- control extra cellular environment

Peto's paradox

Cancer prevalence increasing with lifetime body mass is expected, but in reality the observed rate is constant

Life history trade offs (cancer)

- resources are finite

- predicts animals on the slow continuum have more cancer defenses

- as litter size increases so does rate of malignant cancers

What gene exists in multiple copies on the genome and prevents cancer?

P53

Strategies for controlling cancer

- limit resources

- disrupt cooperation

- prevent host damage

Adaptive theory

Aims to control cancer growth, not to destroy it entirely to prevent resistant cells from taking over

Phylogeny

A visual representation of the evolutionary history of populations, genes, or species

Nested hierarchy

Common descent - new species descended from a common ancestor; no currently existing species is ancestral to any other

Clade

Monophyletic groups

Taxonomic units are legitimate only if...

They represent a clade

Polphyletic ggroups

Organisms that look similar but re not necessarily highly related

Phylogram

Show the amount of change through branch length

Cladogram

Show relatedness without the amount of change or time

Chronogram

Show time when changes occurred

Synapomorphy/homologus

Shared derived traits from a common anscestor

Homoplasy/anaogous

Similar traits evolved from independent evolution

Symplesiomorphy

Shared ancestral trait

Vestigial traits

Evolve in one context in the past but in some species they are retained but they no longer have that function

Domestication pathways

- prey pathway (original hunting leads to codependence)

- directed pathway (humans choose specific animals based on their useful traits to complete a task)

- commensal pathway (animals become attracted to human activities and those that interact positively become domesticated)