This chapter focuses on the process of evolution by natural selection. The chapter begins by describing natural selection and examining the conditions required for evolution to occur. The chapter goes on to consider the evolution of cooperation and examine how selection can promote behaviors that benefit others. Finally, the chapter introduces the concept of sexual selection, a form of natural selection that acts on reproduction and results in many of the morphological and behavioral differences that often exist between the sexes within a species.
Chapter
Evolution and the Study of Animal Behavior
Chapter
The Evolution of Biological Diversity
This chapter covers the evolution of biological diversity. It starts with the concept of
biogeography, which is the scientific study of the geographic distribution of organisms. It
is roughly divided between historical biogeography and ecological biogeography. Phylogenetic
niche conservatism features, which evolutionary lineages retain adaptation to, and
association with, certain ecological factors, rather than adapting to environmental change.
The major historical factors that affected geographic distributions are extinction,
dispersal, and vicariance. The chapter then discusses the impact and aftermath of five major
mass extinctions, which include the extinction of many taxa and nonavian dinosaurs and the
increase in diversity over time.
Chapter
Descent with Modification: Continuity and Variation in the Genome
This chapter talks about DNA replication, and it repairs and ties this topic to Charles Darwin’s concept of ‘descent with modification’, a fundamental principle of natural selection and evolution. It presents several challenges to DNA replication that arise from its length and anti-parallel structure, including the processes that have evolved to address these challenges. It also introduces the many types of mutation that occur, and how the occurrence of such mutations and the effects of selection can be revealed by comparing the genomes of different organisms. The chapter shows how to reconstruct evolutionary history and develop phylogenetic trees based on DNA sequence changes. It highlights the principle of descent with modification, which demonstrates the balance between two competing evolutionary pressures.
Chapter
Introduction to Cells and Cell Research
This chapter focuses on how cells are studied, and specifically examines some of their
basic properties. It discusses the unity and diversity of present-day cells in terms of
their evolution from a common ancestor. Cells share common fundamental properties that have
been conserved throughout evolution. It also investigates complex organisms which are
composed of collections of cells that function in a coordinated manner, noting different
cells specialized to perform particular tasks. The chapter highlights the fundamental
similarities between different types of cells which provide a unifying theme in cell
biology, allowing the basic principles learned from experiments with one kind of cell to be
extrapolated and generalized to other cell types. It analyzes experimental approaches used
to study cells and reviews some of the major historical developments that have led to the
current understanding of cell structure and function.
Book
F. Harvey Pough, William E. Bemis, Betty Mcguire, and Christine M. Janis
Vertebrate Life explores how the anatomy, physiology, ecology, and behaviour of animals interact to produce organisms that function effectively in their environments, and how lineages of organisms change through evolutionary time. It looks at the evolution, diversity, and classification of vertebrates. It considers chondrichthyes, osteichthyes as well as teteapods. Ectothermy is examined as an example of a low-energy approach to life. Other vertebrates considered are turtles, lepidosaurs, crocodylians, and extant birds and mammals.
Chapter
Diversity, Classification, and Evolution of Vertebrates
This chapter explores the diversity, classification, and evolution of vertebrates. It highlights how evolution is central to biology since its overarching principles allow further understanding of how living organisms operate and organize their diversity. Phylogenetic systematics produces branching evolutionary diagrams or phylogenetic trees which show changes in characteristics. The chapter then covers the genetic mechanisms and environmental events that have shaped the evolution and biology of vertebrates. It looks into Earth's history in relation to the evolution of vertebrates and Earth's pattern of fragmentation and coalescence which isolated and renewed contacts of major groups of vertebrates, and which then produced the biogeographic distributions of vertebrates.
Chapter
Cooperation and Conflict
This chapter examines the notion of cooperation and conflict in line with the evolution of
social interactions. It notes how evolutionary biology provides a unique perspective into
how and why families function as they do. Interactions within families allow us to examine
cooperation, while other relationships exhibit the most extreme forms of conflict. Conflicts
may exist among different genes in a species' genome and these are inherited by
different pathways. The chapter also considers extreme examples of cooperation and altruism
in eusocial species, most of which are governed by kin selection and policing by workers. It
mentions how kin and group selection explain three of the major transitions in the evolution
of life on Earth.
Chapter
The Tree of Life
This chapter focuses on the aspect of evolution represented by a phylogenetic tree. It
explains that phylogeny is the study of the history of cladogenetic events and explains how
species or other taxa successfully arose from a common ancestor. The diversity of life has
evolved over so long a time and this has involved hybridization and horizontal gene
transfer. The chapter also notes how phylogenetic methods can be used to explain the history
not only of species, but also of DNA sequences, gene families, tumors and other cell
lineages, and cultural traits. It explains the notion of mosaic evolution wherein different
characters commonly evolve at different rates.
Chapter
The Evolutionary Story of Homo sapiens
This chapter explores the evolutionary story of Homo sapiens. It explains how humans
descended from the last universal common ancestor of all living organisms on Earth,
referencing the fundamental features of inheritance based on nucleic acids, the genetic
code, and proteins composed of L-amino acids. Natural selection and evolution are ongoing in
human populations, even in industrialized societies. The chapter then discusses how
agriculture profoundly changed the environment in which humans were living, which also
resulted in the evolution of culture that enabled humans to occupy more different
environments, over a broader geographic area. It elaborates on the key differences between
cultural evolution and genetic evolution.
Chapter
Mutation and Variation
This chapter explores mutation and variation under the context of inheritance. It
highlights how genetics offers a vast trove of information about the history of life on
Earth and the evolutionary factors acting on living species. The replication of DNA is an
exquisitely precise affair, but errors can still be made which make mutations the ultimate
source of genetic variation in all organisms. Generally, mutations come in various forms and
these differ in how much of a genome they affect. Some species have mechanisms that
contribute to inheritance and play a role in evolution regardless of genetics.
Chapter
Genetic algorithms
This chapter talks about genetic algorithms (GA), which are considered an optimization technique. This is, in other words, an intelligent way to search for the optimum solution to a problem hidden in a wealth of poorer ones. It explains that a GA works with a ‘population’ of individuals. It also clarifies how the individuals ‘mate’ with each other, ‘mutate’, and ‘reproduce’ in order to evolve through successive generations toward an optimum solution. The chapter discusses what characteristic of evolution acquires the ability to provide the inspiration for solving numerical problems and how its power can be harnessed in a most effective and intriguing way. It mentions the similarities of GA with other optimization and search methods in which any computational task involves mating, mutation, and reproduction.
Chapter
Developmental Mechanisms of Evolutionary Change
This chapter centers on evolution, which is the result of inherited changes in development and contributes to modifications of embryonic or larval development. It discusses the modularity of development that allows parts of the embryo to change without affecting other parts and is caused by the modularity of enhancers. It also considers the recruitment of existing genes and pathways for new functions as a fundamental mechanism for creating new phenotypes. The chapter details how new anatomical structures may result from duplicated genes whose regulation has diverged. It outlines the ways evolutionary change is affected through development at the level of gene expression: change in location (heterotopy), change in timing (heterochrony), change in amount (heterometry), and change in kind (heterotypy).
Book
Lewis Wolpert, Cheryll Tickle, Alfonso Martinez Arias, Peter Lawrence, and James Locke
Principles of Development starts off by presenting some background history and basic concepts. The next chapterIt then looks at is about the Ddrosophila life cycle and the development of the body plan. Other topics covered include vertebrate life cycles, experimental techniques and human development, and the vertebrate body plan for Xenopus and zebrafish and the chick and mouse. Other chapters look at the development of nematodes and sea urchins, morphogenesis, cell differentiation and stem cells, and germ cells, fertilization and sex. The text then goes on to look at organogenesis, the development of the nervous system, and the growth, post-embryonic development, and regeneration. Finally, the text looks at plant life cycle and development, evolution, and development.
Chapter
Why did evolution explode in the Cambrian?
This chapter evaluates the Cambrian explosion. This burst of animal diversity has been interpreted as marking an unusually inventive period of evolution, with a greater rate of change in fundamental features of body plan than has ever occurred before or since. The Cambrian explosion presents two challenges to Darwinian gradualism: explaining evolution of novel features for which we have little direct evidence of intermediate forms, and explaining why animal phyla appear in a particular time period and not before or since. One proposed solution to both these challenges is that body plans evolved not by a long series of gradual changes but by relatively few changes to developmental genes that allowed new distinct new forms to be generated without intermediates. The chapter then assesses whether such ‘macromutations’ are possible, and if it is plausible that they could give rise to a successful lineage of animals with a novel body plan.
Chapter
Is sex good for survival?
This chapter addresses the evolution of sex. Sex results in offspring with DNA from more than one parent. Sexual reproduction is so common and familiar that it may come as a surprise to find that it has been an enduring puzzle in evolutionary biology. Given that many species can reproduce uniparentally, without needing to combine genes with other individuals, why would sex evolve? And given that asexual lineages frequently evolve from sexual species, why do so many different species retain sexual reproduction? Many different solutions have been proposed for both the origin and maintenance of sexual reproduction, ranging from genome repair to long-term evolvability. This broad range of proposed mechanisms requires us to think about how evolution works at different levels of biological organization, from ‘selfish genes’ to evolutionary lineages, and at different timescales, from individual lifetimes to millions of years.
Chapter
Hypotheses
Seeing the wood for the trees
This chapter illustrates how phylogenies can be used to test hypotheses about evolutionary past and processes. There are many possible phylogenies that could explain how we ended up with the DNA sequences we have observed. Phylogenetic analysis is a way of generating and comparing different hypotheses for the evolution of a set of sequences, so requires a criterion for choosing the most plausible history. Most methods compare the plausibility of different phylogenies, using a model of molecular evolution which states the relative probability of different kinds of sequence changes. The strength of support for different possible phylogenies can be compared by asking whether slightly different data, or differences in the analysis, would have produced the same result. Phylogenies can also be used to test hypotheses about evolution by asking what patterns we would expect to see if the hypothesis was true.
Chapter
Replication
Endless copies
This chapter examines DNA replication. The evolution of life depends on hereditary information being copied from one generation to the next. Thus, a basic grasp of DNA replication is essential for anyone wishing to understand evolution. Moreover, familiarity with the processes of DNA replication is the key to understanding many molecular techniques. DNA amplification (making millions of copies of a DNA sequence in the laboratory) relies upon the domestication of the DNA copying processes that occur in living cells. Understanding DNA replication is also central to appreciating the nature of biological information stored in DNA. DNA replication creates a nested hierarchy of differences between genomes that reveals the relationships between organisms and the processes of evolution.
Chapter
The Dynamic Genome
This chapter studies the genome itself, which is the source of all the hereditary information underlying the adaptation of organisms to their environment. The evolution of the genome is naturally one of the most pressing issues in evolutionary biology. Why are many genomes much larger than they need to be? How does the gain and loss of genes contribute to evolution? How do new genes come into being? Molecular genetics is beginning to provide answers to fundamental questions like these, and the answers have turned out to depend on the Darwinian rules that govern genome dynamics. The chapter then considers how evolving genomes diverge, how genes are modified at different rates, how eukaryotic genomes have evolved novel features, and how genetic elements may evolve cooperation or conflict.
Chapter
Chromosome Mutations
This chapter discusses chromosome mutations, during which one or a few chromosomes may be lost or gained (aneuploidy). Common aneuploid conditions include monosomy and trisomy; nullisomy and tetrasomy also occur. The addition of whole sets of chromosomes produces polyploid cells. Meanwhile, segments of individual chromosomes can be deleted, duplicated, become incorporated in other chromosomes, or inverted. Chromosome mutations often arise through errors during meiosis. In turn, chromosomal mutations frequently disrupt the process of meiosis, resulting in unbalanced gametes. The chapter then looks at how changes in chromosomal structure and number often occur in tumour cells. It also considers how chromosome mutations play important roles in evolution.
Chapter
Island Biogeography
This chapter focuses on island biogeography. It shows how islands have always had a great influence on ecology, evolution, and biogeography. For mainland systems, the diversity of insular biotas is often simply characterized by their species richness, which refers to the number of species of a particular taxon. The chapter then looks at the patterns and causal explanations for differences in species richness among islands. It also details the ecological and evolutionary assembly of insular biotas, noting that the depauperate and disharmonic evolutionary arena of remote islands establishes ecological naiveté, one of the most perilous characteristics of insular plants and animals.
