Neanderthals evolved greater intelligence independently

A rare find of Neanderthal fossils or subfossils shows that early Neanderthals were small-brained and developed larger brains independently of the line that led to us.

As best we can tell, humans and Neanderthals diverged from a common ancestor about 500,000 years ago, a species called Homo heidelbergenesis. Modern humans appeared in Africa some 300,000 years later, a time when Neanderthals were already romping around Europe and Asia.

These skulls are 430,000 years old. They have a small  braincase but in other respects have Neanderthal characteristics.

…the Neanderthal trait of an elongated and rounded brain case came later.

Invasive species old and new

The Winnipeg Free Press reports on six species that have moved out of their home grounds and become a nuisance in Canada or the U.S., doing ecological damage: the Asian carp, the American bullfrog, Burmese python, killer bees, zebra mussels, and purple loosestrife.

“Stars hung suspended” — robot camera finds ice-dwelling anemones

A robot camera in the Antarctic Ocean found something that no one was looking for: bloodless sea anemones anchored to the underside of the Ross Ice Shelf. The researchers, from the University of Nebraska, dropped their camera-robot through the 270-metre-thick ice to explore sea currents and test their machine. The team did not include any biologists but they preserved some of the tiny animals for later study. These are the first anemones found that live in or on ice: ANDRILL team discovers ice-loving sea anemones in Antarctica. They are only a couple of centimetres high.

“The white anemones have been named Edwardsiella andrillae, in honor of the ANDRILL program.” I guess we’ll have to look at PLoS One to discover why they were placed in Edwardsiella so quickly. (the anemones, not the bacteria): Edwardsiella andrillae, a New Species of Sea Anemone from Antarctic Ice.

The large-scale image of the discovery is stunning.

Ice-dwelling anemones

Placoderms evolved penetrative sex

Placoderms are an extinct class of armoured fishes containing several orders. Placoderm comes from Greek words for “plate” and “skin.” They are jawed fishes, but so ancient that they precede both sharks & rays and bony fishes: some elements of the skeleton are cartilaginous while others are bony and there are bony elements in their skin armour. Yes, bones and teeth are derived from skin tissue. They appeared in the fossil record about 420 Ma in the Early Silurian and by 400 Ma in the Devonian all major placoderm orders were present. (See “Australia: The Land Where Time Began: Placoderms“.}

402px-Dunkleosteus_terrelli_2 (From Wikipedia)

Before placoderms, all fertilization of eggs by sperm occurred outside the body, as females released eggs and males released sperm into the water. They might hover near each other, but if sperm found egg it was partly by chance. Female fishes release their eggs through a cloaca, an opening for both eggs and bodily wastes. As the fish that were closest had the most success, eventually males began to position themselves at the cloaca. One group of placoderms, the ptyctodontids, have these external claspers to hold the female, as do sharks. The pelvic fin perhaps developed a tube shape to funnel the male’s sperm into the female’s cloaca. Some modern fish mate in this way. What is known is that some placoderms gave birth to live young, which means that that at the very least, eggs were fertilized while still in the female. In short, these early fishes invented internal fertilization.

Two prehistoric fish swimming

Rhamphodopsis threiplandi, a placoderm with claspers (from Wikipedia)

There are two pathways after internal fertilization. One is ovivipary, where eggs are retained and hatch inside the mother, who then expels the young. Some sharks still do that. In fact, in some sharks the first young to hatch eat the other eggs to nourish themselves until birth. Females may develop areas of nourishing skin that the young can scrape off. The other main path is for the young & the female to cooperatively grow a placenta, which attaches to the her and extracts nourishment from her blood. (Placentas could  not have happened without a retrovirus inserting itself into the genome, but that’s another topic.)

At first, scientists thought that young placoderms inside larger fossils could have been evidence of predation; but at last a tiny fossil placoderm was found with a tiny umbilical cord, still attached to the mother.

Dolphin epizootic

Researchers have detected morbillivirus in the bodies of dolphins that died off the Atlantic shores of the U.S. They conclude that there’s an epizootic affecting the younger dolphins that have never been exposed to that virus.

Here’s more about the epizootic and other dolphin die-offs from previous years.

Morbillivirus is in the same viral genus as the viruses for measles and rinderpest.

“Only a theory” debunked

There are some arguments based on misunderstanding of how words are used in science, or deliberate mis-use by creationists. Just as Microsoft Windows is different from house windows, so in science “theory” means well-tested explanation, not a notion. Hypothesis means explanation that can be tested, not wild-assed guess. Here are seven science words that we need to learn, or perhaps that scientists should simply stop using. I’m in favour of replacing “theory of evolution” with “explanation of the mechanics of evolution” to start with:

“Just a theory”: Seven mis-used science words

Penicillin breeding experiments!

Scientists used their understanding of the MAT (mating) genes to induce penicillin mold to reproduce sexually, producing spores with new gene combinations. They hope to breed new strains that will kill antibiotic-resistant disease germs. And now that they have induced penicillin to breed, instead of merely producing identical spores, for the first time in a hundred years, they’ll try the same with other important fungi, such as those that produce other antibiotics.

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