week 1 Flashcards
What is the purpose of reproduction? (3 points)
Parental generation produces offspring, the first filial generation (F1)
Mechanism by which parents generate the first filial generation
F1 generation acts as parents to the second ilial generation (F2)
Is the purpose of reproduction to produce the F1 or F2 generation? In other words what does evolution care about?
Evolution cares about the F2 generation. Selection pressures act on the second generation, species are not going to evolve unless the F1 survive to produce F2
What is the word definition of lifetime reproductive output?
Number of offspring being born to a parent or parents (asexual or sexual) in the F1 generation.
what is the mathematical equation for LRO?
Product of fecundity (Fertility) x fertile life span
What determines LRO?
Fecundity
What determines fecundity? (4 p oints)
The number of offspring it produces.
Number of fertile matings (mate density, success in courting, success in mating act)
Fertility of an indv. (number of gametes produced)
Fertility of partner in sexual reproduction
What is a semelparous species and give an example.
Single episode of reproduction before death.
Pacific salmon
What is an iteroparous species, and what are the different kinds?
Several rounds of reproduction before they die.
Monogamous or polygynous or polyandrous
What 2 things determine the fertile life span?
Age at first fertile mating and age at last fertile mating
The age at the first fertile mating depends on what factors?
How quickly an organism develops. Precocious individuals obtain sexual maturity at an early age.
Define precocious
Sexual maturity reached at an earlier age than usual
What is the age of the last fertile mating often determined by? But what are the 2 exceptions
Death. However, elephants and humans exhibit menopause.
What is the lifetime reproductive success?
The number of offspring born to a parent in the F1 generation and the number of offspring attributable to a grandparent in the F2 generation.
Goes beyond LRO as it is how many genes are passed down to F2.
Give an example of when the LRS is much lower than the LRO?
In sterile animals such as hybrids like mules. THe F1 generation is produced the mule, but no further generations are produced.
What determines life time reproductive success? (3 points)
LRO
Fecundity / fertility of F1
Probability that F1 survive to sexual maturity / achieve fertility
The LRS will always be lower than LRO as it is a probability.
What are the 7 types of asexual reproduction?
Binary fission Multiple fission Budding Fragmentation Vegetative propagation Parthenogenesis Apomixis
Explain binary fission
One parent cell splits into 2 identical daughter cells.
The parental cell ceases to exist.
Archaea and Eubacteria
Explain multiple fission
One parent cell replicated nucleus then splits into several identical daughter cells
Patenral cell ceases to exist
Explain budding
Daughter cell divides from mother cell.
Parent cell still survives (this is how it is differentiated between binary fission).
Yeast and Hydra
Explain fragmentation
Offspring regenerate from fragments, fissiparity.
Turbellarians, starfish, annelids
Explain vegetative propagation
Like fragmentation with plants.
Strawberry runners.
Take a fragment of plant and plant it then a new plant grows