Skip to main content

Posts

Showing posts with the label offspring

Fossil Shows Neanderthals and Denisovans Interbred

A fragment of a long bone from a hominid at least 13 years old shows that it had a Denisovan father and Neanderthal mother. The specimen was found in Denisova Cave in Russia in 2012. Because it was found indicates that other cross breeding occurred. Neanderthals obviously migrated to eastern Eurasia from western Europe. They were not "stuck" in regions around the Iberian Peninsular. Genetic analysis shows that the father of the Neanderthal/Denisovan adolescent also had some Neanderthal ancestry, so the groups were coexisting in the east. It is believed by scientists that Neanderthals interbred with humans and had fertile young. However, this is not possible as Neanderthals have 24 pairs of chromosomes while humans have 23. Interbreeding of Denisovans and Neanderthals could occur as they both had 24 pairs of chromosomes. + so denisovan is neanderthal us dna ox humans a denisovans i fossil oh mother ah genes by mixed id years + ~ ha denisovan in neanderthal on dna an hum

One Hundred Million Species Remain Unnamed - Biology

Biology - 100 million unnamed species exist on the planet. We know that many species on the planet are dying out. Apparently, we have nothing to fear. Though 2 million species have been named, a massive 100 million more are out there. This does not include currently unnamed bacteria. Each living creature is placed in a species category because it has independent evolutionary lineage. A horse and donkey for example are different species, but they both have a common ancestor. If they do breed their offspring are infertile. There is debate about this with claims that some mules have had young. This gets into the argument about Neanderthals breeding with humans when they have a different number of chromosomes. Interbreeding should not be possible. Brewer's Sparrow The problem with naming is that animals from two species can look virtually identical. The African elephant is a misnomer. There are actually two species: the bush elephant and the forest elephant. One

Humans Crossing With Neanderthals and Denisovans is Rubbish

Much has been said about humans having mated with neanderthals. Scientists claim that all of us have Neanderthal genes. There is the real issue of humans and Neanderthal having a different number of chromosomes. It is known that if a horse is mated with a donkey, the result is an infertile mule. This holds true for all species, so how is it possible for two type of man who branched away from each other a very long time ago to have fertile offspring - the answer is it isn't possible. Another issue is the premise that Denisovans mated with Man. There is little evidence for this. Currently, we do not know the number of chromosomes Denisovans had. Yet most scientists treat the mixing hypothesis as fact. Can scientists be wrong? They have of course been very mistaken in times past and the present is no different. Why do specialists accept theories that have not been tested by the well know scientific method. It must be the case that most of them accept that Santa exists and

Eggs of Mussels Attract Compatible Sperm by Releasing Chemicals

Mussel sperm have to find the right egg. This is not as easy as it seems. When the eggs are released they can be scattered through ocean water or river. While mussels are attached to rocks, eggs and sperm are at the mercy of the elements. The eggs have to let sperm know that the eggs are available, so they send out a chemical message to attract suitable sperm. Many species release chemical signals. The message sent has to be differentiated to prevent fertilization by siblings. A test was done forcing sperm to fertilize chosen eggs. Only compatible matches gave healthy offspring. In a later test mussel sperm were observed to choose compatible eggs to produce health young. This is the first time chemical attraction has been observed in mussels. It shows how important compatibility is in many species. This brings into question the theory of gene pools where there is deemed to be no barrier to gene pairing. The idea that any male and female can have offspring no longer stan

Smoking Damages Your Health - Quickly

Some new medical findings can be a bit "oh-hum". It has been found that smoking, just intaking smoke from one cigarette, can damage DNA almost immediately. This does make one think about not taking up the habit. However, it is widely accepted that danger is only there after smoking for 20 or 30 years. So much work has been done on tobacco. Very little on the other widely used smoking drug - marijuana. Stay away from cigarettes one may say and partake of weed instead. Apparently, the intake of grass is quite safe. Why is there such a desire for humans to consume such a highly addictive naturally occurring compound? It all boils downs to evolution, natural selection. Unless something you consume reduces your competency to reproduce until the age of about 25, genes will not be selected to combat it. Whether smokers die later in life when they are way past producing and bringing up offspring is irrelevant to survival of the species. Smoking is like drinking alcohol - it is enjoy

Ocean Dead Zones Could Cause Mass Extinction

The number of oceanic dead zones in the world is increasing. In the zones oxygen levels are too low to sustain life. It is widely know that a monster area in the south Atlantic is growing in size, but there are hundreds more smaller dead zones. They are caused by overfishing and the nutrient rich residue in fertilizer runoff. Climate change also plays a part. As oceans warm up layers form and some become stagnant with low oxygen levels. Long standing currents and wind directions have changed which has reduced layer intermixing. Since 2000 over 400 dead zones have been identified. In the 1980s there were little more than a hundred. Some are huge, more than 70,00 sq kilometers, while many are less than a square kilometer. The lack of oxygen not only causes death. Offspring are born deformed. They do not survive, or produce fewer young. Danger of a mass extinction is now very high. Dead zones are forming on continental shelves where most fishing is done. The mere presence of humans is dee