Untitled Flashcards Set

What is biological evolution?

The scientific theory that states that living things have diverged from the same ancestors.

sexual selection

where certain traits increase an individual's chances of attracting mates and reproducing

differential reproductive sucess caused by

• sexual dismorphism

• mating and courtship behaviours

• ability to attract mates

monoculture

the same varieties of species over a large area of land = more vulnerable to disease/environmental conditions

allele frequency

how often a specific form of a gene (allele) appears in a population, helps us to understand variation.

biotechnology

the use of living organisms or biological systems to develop products or solve problems. e.g. medicines, vaccines.

gene pool

the complete set of all alleles (gene versions) in a population.

population

group of organisms of the same species living in the same area at the same time, and capable of interbreeding.

development

• Physical changes that occur during an individual’s life, resulting from growth or the natural aging process

  • Cosmetic alterations and scars are non-inheritable traits 

dangers of artificial selection

creation of a monoculture, might not be able to survive in the wild, links to genetic disorders

selective pressures

things that influence reproduction and survival - ie. biotic/abiotic factors, disease, predators, climate, food availability

homologous features

features that have the same structure but have evolved for different purposes

analogous features

features that look different but are used for the same purpose

vestigial features

structures that are non-functioning or barely functioning because they have no use for the conditions that the organism is living in

biogeography

study of geographic distribution of organisms based on living species and fossils.

what are the source of genetic variation

mutations

how do you know if a new species has been formed

if they have sterile offsprings

what are morphological features

The physical characteristics of an organism, such as shape, size, color, and structure.

embryology -

development processes and patterns among embryos, animals with a common ancestor have similar embryos

DNA sequencing

all living thing have the same base genetic code because we are all derived from a common ancestor but the closer the DNA sequences, the less the genetic variations

what does VIS stand for

variation, inheritance, selection

What does the term 'selective breeding' refer to?

When artificial selection is used to create an ideal offspring.

what are the similarities between artificial selection and natural selection (5)

• occur over a period of time

• varies gene pool

• can lead to a formation of a new species

• cannot change/alter the phenotype of the organism during its lifetime

• can only alter phenotypes of offspring yet to be born by manipulating the parents’ phenotypes

What are structural adaptations?

Physical features that enhance survival and reproduction such as fish scales or hollow bones in birds.

What are the types of adaptations?

Structural, physiological, and behavioral adaptations.

transitional forms

fossils or species that are intermediate in form between 2 other species in a direct line of descent AKA direct line

what is domestication

The process by which humans alter the genetic traits of wild animals and plants through selective breeding for useful traits.

can harmful, beneficial and neutral mutations be affected by the environment

yes, neutral mutations can become harmful or useful, beneficial mutations can become harmful and harmful mutations can become beneficial

What is a neutral mutation?

A mutation that does not confer any selective advantage or disadvantage.

What is the significance of mutations in evolution?

They create new genes that provide a continual supply of new genetic information.

What is the difference between microevolution and macroevolution?

Microevolution involves small changes within a population, while macroevolution covers large-scale changes that can lead to the formation of new species.

Define natural selection.

The process by which the environment favors the reproductive success of certain individuals within a population.

how does natural selection occur

by changes to DNA base pairings

What is adaptive radiation?

The rapid evolution of diverse species from a common ancestor, typically when colonizing new environments. e.g. darwin’s finches  on the Galápagos Islands evolved into different species with distinct beak shapes to exploit different food sources.

What is speciation?

The formation of a new species.

What is allopatric speciation?

The formation of a new species due to geographic isolation.

What is sympatric speciation?

The evolution of populations into separate species within the same geographic region.

What is the role of embryology in supporting evolutionary theory?

Embryology shows that different species have similar traits as embryos, indicating a common ancestry.

What did Charles Lyell contribute to evolutionary biology?

He proposed uniformitarianism, which suggests that geological changes are slow and continuous.

What is genetic drift?

Changes to allele frequency due to chance events, more pronounced in small populations.

what is the bottleneck effect

a sharp reduction in the size of a population due to a chance event, leading to a loss of genetic diversity because only a small group of survivors contribute to the gene pool.

what is the founder effect

when a group of individuals separate from their population and form a new one. common alleles may become rare and vice versa

What does the term 'gene flow' mean?

The transfer of alleles from one population to another, introducing new genetic material.

What is the role of competition in evolutionary theory?

It drives natural selection by limiting resources and promoting survival of the fittest.

What evidence supports the theory of evolution?

Fossil records, biogeography, comparative anatomy, embryology, and DNA sequencing.

What is a synapomorphy?

A derived trait shared by two or more species/groups that indicates a close evolutionary relationship.

How do catastrophic events relate to evolution?

Catastrophic events can lead to mass extinctions, allowing remaining species to repopulate and evolve in newly available niches.

what are fossils?

ancient remains, traces or imprints of organisms preserved in rock or other mineral deposits in the earths crust. fossils are ordered with the newer ones closer to the top and the older ones closer to the bottom.

What is macroevolution?

Large-scale evolutionary changes that occur over a long period.

What is the Cambrian Explosion?

A rapid evolution of most major animal phyla that occurred approximately 542 million years ago.

What is the significance of the Archaeopteryx fossil?

It is a transitional form showing features of both birds and primitive reptiles, providing evidence for evolution.

what is the theory of punctuated equilibrium?

a theory that suggests evolution occurs in rapid bursts

what is catastrophism?

the theory that catastrophes such as floods, landslides and earthquakes occur which wipe out the current population, allowing neighbouring species to repopulate the area

malthus’s theory of population (3)

in a generation, there are more offspring than parents. populations continue to grow in size. food and other resources are limited.

Lamarck’s two principles

1. use and disuse - a structure used more often becomes stronger and a structure used less often becomes weaker

2. inheritance of acquired characteristics - individuals could pass on traits they had inherited during their lifetime

why was lamarck’s theory flawed

although characteristics may be acquired, many features do not change in response to use - features that change arent normally heritable

mechanisms of evolution

natural selection, mutations, artificial selection, sexual selection, genetic drift, gene flow

directional selection

the extreme phenotype is favoured over the others, popular in artificial selection ex. moths

stabilizing selection

the average is preferred over the extreme, ex. baby weight

disruptive selection

two extremes are preferred over the average. ex. rocket pocket mice are either light to blend w sand, dark to blend w volcanic rock

founders effect

when a small part of the population breaks off and forms a new population

hardy-weinberg principle (5)

small population - increases likelihood of genetic drift, horizontal gene transfer - gain alleles from different species, immigration and emmigration - alleles added or removed , mutations - introduces new alleles to a population, natural selection - favours passing of alleles over others

What is A Species? - Biological Species Concept, ernst mayr

a group of organisms that can interbreed and produce fertile offspring and are reproductively isolated from other groups

prezygotic isolation mechanisms

behavioural, - different species, different courtship behaviours to get noticed

ecological, - very similar species occupy different habitats to prevent them from breeding with each other

mechanical, - males and females from the same species have sex organs that align with each other to work

temporal, - species breed at different times in a year

gametic - male sperm and female eggs of a same species can recognize each other

postzygotic isolation mechanisms

hybrid inviability, - a hybrid develops but is inviable and either is miscarried or does not reach maturity

hybrid infertility, - is develops and healthy but cannot produce offsprings

zygotic morality - mating and fertilization is possible but the zygote is not viable

divergent evolution

species that once shared a common ancestor became increasingly distinct

covergent evolution

species that live separately develop with similar traits due to environmental conditions

coevolution

one species evolves in response to the evolution of another species

abiogenesis

origin of life from non-living matter

phylogenies

classification of species based on morphology, genetics and fossil record

cladogram

linear pattern of evolutionary relationships

cladistics

method of determining evolutionary relationships based on the presence of absence of traits

derived traits

new traits that have branched off due to adaptations

synapomorphy

derived trait shared by two or more species/groups which makes them more closely related to each other

theory of gradualism

large changes occur after the accumulation of small changes

why are both gradualism and puncuated equilibrium true?

if there were no changes in the environment occuring = evolution would be slow and gradual

if the environmental conditions were rapidly changing = rapid evolution

ex. after mass extinction, species enter new environment with far fewer competitors

why are there gaps in evidence

species with delicate bodies dont fossilize easily, environment may not have the conditions for it

implications of mutations

viruses can mutate in your body to adapt the the antibiotics being given, stopping them from working

mimicry

when one species evolves to look, sound or act like other species to gain an advantage