Tools of Evolutionary Biology Summary

Some female reptiles will guard the eggs they lay, and others will not, but egg guarding is about as far as parental care typically goes. Alligator mississippiensis is one of the rare exceptions to this common reptilian trend. Gravid female alligators will build nests, lay the eggs, and protect them from possible predators. When presented with a possible threat to her clutch, the female will hiss, or lunge at the perceived predator (Kushlan, 1973). Come hatching time, she may open the nest or help the juveniles out of their eggs, and carry them in her mouth to the water (Passek, 1999). In some cases, males have assisted the hatching of the offspring by breaking open the eggs, similar to the female. According to Passek, hatchlings communicate with each other while still in the eggs by using vocalizations. When hatched, these vocalizations are calls that alert the mother to possible distress.

In insect species with indirect sperm transfer, sperm is packed in a spermatophore that is either externally attached to the female 's genital opening or introduced into her bursa copulatrix. Sperm transfer is not immediate in these species, and consequently mate guarding has been suggested to function as a mechanism of guarding sperm until it is released from the spermatophore into the female (i.e. spermatophore guarding). Spermatophore guarding is relatively common in insect species with external spermatophores (e.g. Orthoptera; Alcock 1994; Simmons 2001), but supposedly absent in species with internal spermatophores and rapid sperm release (Simmons 2001). This study focuses on two hypothesis associated with mate guarding a tactic of many species that adjust their reproductive behaviour according to the apparent risk of sperm competition. The phenomenon of mate guard to consider sperm competition levels and evolution of internal spermatophore guard is wide spread in insects and other animals. We analyse two hypothesis one the rival exclusion followed by the next spermatophore renewal hypothesis. Results showed that as rival was introduced to the arena of mating of the distinctive original male (guard) in many cases showed a strong aggressive behaviour regardless of whether successively avert the rival. In the second hypothesis certainly majority of the incidents showed an attempt of

the genetics of this specific jumping spider upset the protective system of the ants. Not only do

The data presented in this paper partially supports our hypothesis that the rise in helper pool size of the black-tailed prairie dogs increases breeders’ long-term reproductive success; however, we found there is a limit to this trend. The graphs constructed from our data displays a steep slope within a 2 to 8 helper range (Graph 1). This demonstrates that within this range an increase in helper pool size directly increases the breeders’ fitness through long-term reproductive success. Therefore, our results support Hoogland’s prediction that black-tailed prairie dogs the greater the helper pool size the more improved long-term reproductive success became, but only within this range. In addition, acorn woodpeckers also demonstrate a similar

Viviparity (live birth) is a highly uncommon form of reproduction in the insect world, those that do have this type of reproduction fall into two main groups: those who have a high offspring rates and those who have low offspring rates. Viviparity, while uncommon, does serve a distinct purpose. In some cases the insect has very few ovarioles to begin with, in which case, it is essential for the offspring to be given the best chances at survival they can get. Having the embryo safely protected inside the insect while it develops gives the young insect a far better survival rate than those who are deposited in eggs outside the mother. In other cases, such as with Aphids, it allows for a ‘telescoping generations’ effect which greatly increases the numbers of

A species’ long-term reproductive success is the most important factor when determining whether that species cooperatively breeds. Cooperative breeding is when an individual forgoes reproducing to assist offspring that are not their own (Hoogland 1983). Although there is an absence of direct fitness, individuals still gain genetics benefits through kin selection (Queller & Strassmann 1998). Kin selection allows some of the individual’s genes to pass on to the next generation by helping his or her relatives, who carry similar genes, to raise their young (Queller & Strassmann 1998). Individuals that help their kin raise their young, also known as helpers, perform tasks, like feed, groom, and watch the young. They also protect the territorial boundaries and alert other individuals of incoming threats (Jennions and MacDonald 1994). The best way to analyze the effectiveness of cooperative breeding is through a species’

stay alive. When the female is ready to lay her eggs, she drops of the

Predation is an interspecific interaction in which one species (the predator) captures, kills, and eats another (prey). Predation removes a prey individual from the population immediately. Different types of predators have different functional responses, meaning they differ in how changes in prey density affect the rate at which they kill prey. The set of alleles that is carried by an individual’s chromosomes is known as genotype. An individual’s observable traits is known as phenotype. Natural selection is a simple mechanism that causes populations of living things to change over time. In fact, it is so simple that it can be broken down into five basic steps: Variation, Inheritance, Selection, Time and Adaptation. Natural selection occurs

Charles Darwin was an English naturalist, geologist, and biologist who lived from 1809 to 1882. Darwin is most famously known for his contribution to evolutions. He published a book known as The Origin of Species by Means of Natural Selection. This book emphasizes two theories known as descent with modification and natural selection. Descent with modification is a common ancestry between organisms. Natural selection is the process where organisms slowly change to be better adapted to their environment. Traits that lead an organism to have success in its lifetime are passed down to the next generation. Taits not well suited for their environment usually lead an organism to death before the organism can reproduce. Once an organism dies it genes die with it. In order for changes in the organism's phenotype to occur, an organism's genotype must be changed. This can occur by genetic mutation. Mutations are changes in an organism's DNA. A single nucleotide change can have a large effect on an organism's appearance. Gene flow which is any movement of genes from one population to another is a large source of genetic variation. Both mutations and gene flow can cause

For example, Mumme (1992) found that removal of non-breeders in the Florida scrub Jay had no significant effect on breeder survival, clutch size, or hatching success. In addition, Mumme discovered the removal of non-breeders costs experimental groups suffered higher rates of predation on nestlings and lower rates of fledgling survival (Mumme 1992). Through some further analysis of the data, Mumme states that it was not only the presence of non-breeders, rather it was how much the non-breeders helped that attributed to the increase in long-term reproductive success (Mumme 1992). In other words, the more a non-breeder helped raise young, long-term reproductive success increases. Nevertheless, long-term reproductive success having a direct correlation with the number of helpers is usually a strong indicator of cooperative breeding (Koenig 1981); however, it is unknown in some species, like black-tailed prairie dogs. The black-tailed prairie dogs provide a great opportunity to study what factors contribute to their long-term reproductive

The matter of Natural Selection was brought forth by Charles Darwin and with that evolved the concept of Sexual Selection. The first thing that may come to mind is male preference in females for reproductive purposes. It is quite common when thinking about the process of Natural Selection. We don’t typically take notice of Darwin’s recognition or acceptance for “female choice” upon mate selection and the role it plays in our evolution. Both males and females differentiate when it comes to parental investment. Therefore selection of the opposite sex in order to benefit their kin is a valuable choice. We know that amongst men typically their preferences are based on physical attractiveness; so then what drives females. In attempts to better understand what and how females make their decisions in benefit for themselves and their offspring and how they have possibly evolved. We will look at a variety of ideas that have been formed in the research attempted to get a better understanding of this topic.

Females are the choosing sex, for they are usually the ones who invest more in their offspring—from the birth to the nurturing (Stanford 100). Second,

The second reason is the expansion of resource allocation to offspring quantity versus quality that can account for observations socioecological and individual levels of variation in fertility.

Their conclusion was that kinship does confer higher fitness and that relatedness does play a role in the decision on which subordinate gets to forage and migrate to other territory. This conclusion was supported by the observation that related subordinates that migrate to a different territory spent more time together in the patch and fed more than the non-kin

Androgens are involved in the environmental plasticity of begging in both the parent and the offspring. These interactions probably occur within the egg,