The evolution of prokaryotic bacteria in ancient seas 3.8 billion years ago; how cyanobacteria evolved to use visible light as a source of energy; the appearance of stromatolites in ancient seas; how the evolution of eukaroyotic cells led to the appearance of sea algae; how sea algae adapted to living on land to form the first land plants, the bryophytes. Some adaptions that prevent the dessication of bryophytes.
This science artilce investigates convergent evolution in different organisms and how two totally unrelated species can evolve to resemble each other in different ways. We investigate convergent evolution in color, body shape, body organs, defensive spines, tongues, eyes, animal behavior, brain function, mimicry and in extinct species. We also look at convergent evolution in animals, plants, fish, insects and reptiles.
Reasons for the evolution of eyesight during the period known as the Cambrian explosion; how the evolution of eyesight resulted in organisms becoming either prey or predators. An explanation of how eyesight evolved through eight simple steps; recessed light sensitive cells, the pin hole eye including a description of the eye of the nautilus mollusc; the spherical lens with greater refractive powers.
This science blog examines the differences between constrictor snakes and venomous snakes; how the two different types of snake kill their prey in different ways. Using Homer as an example, we explore negative reactions to snakes and try to counter these negative reactions. We looks at some reasons why snakes have a place in any eco system and what would happen in an eco system if there were fewer snakes.
This is the first of two science projects that investigate the evolution of snakes. We learn how snakes evolved from lizards one hundred and twenty million years ago when Cretaceous lizards hunted food underground. We investigate evolutionary features that distinguish snakes from lizards including their long backs, absence of limbs, unique eyes and unique way in which they eat and digest their food.
This article gives an example of evolution by natural selection which takes place over a very short period of time. The article summarizes the work undertaken by the evolutionary biologist Dr Endler, whose experiment under laboratory conditions saw guppy fish change the color of their skins in just over a year. His laboratory work replicated his observations in the field in mountain streams.
The reasons behind the taming of wolves in prehistoric times which preceded the evolution of the domestic dog. Plausible theories explaining how wolves first became tamed through processes of both ‘artificial’ and ‘natural’ selection. We then take a look at the exciting project started in the 1950’s by a Russian biologist which successfully bred tame foxes from wild foxes within only a few generations.
We look at ‘evolution by artificial selection’; we investigate how human activity has shaped and sculptured the physical appearance of certain organisms; the evolution through artificial means of fancy pigeons, cows, dogs, wild cabbage and (perhaps!) a certain crab; an introduction to Charles Darwin and the contents of the first chapter of his book,’Origin of the Species through Natural Selection’.
This school science article looks at the evolution of the ‘beach mouse’, a subspecies of the ‘Oldfield’ mouse, (Peromyscus polionotus) which inhabits barrier islands in Florida and Alabama. The article examines the evolutionary pressures 6000 years ago which led to Beach mice evolving light colored coats and discusses the issues that arise within the context of ‘evolution by natural selection’.
Evolutionary development of the elephant seal from its distant ancestor, the Puijila darwini which lived in the Canadian Arctic 25 million years ago; the evolutionary pressures which led to descendants of the Puijila adapting and changing to form new species;how intermediate ancestors became less ‘Puijila like’ to more ‘elephant seal like’; the adaptions which make elephant seals amazing hunters.