Sunday, January 17, 2021

The Amazing Platypus


Platypuses are weird creatures. They are so unusual that it took taxonomists more than eighty years to determine what they are.

An international team of researchers, led by University of Copenhagen biologists, has mapped a complete platypus genome. The study is published in the scientific journal, Nature.

"Australia's beaver-like, duck-billed platypus exhibits an array of bizarre characteristics: it lays eggs instead of giving birth to live babies, sweats milk, has venomous spurs and is even equipped with 10 sex chromosomes. Now, researchers have conducted a unique mapping of the platypus genome and found answers regarding the origins of a few of its stranger features."

One of the platypus' most unusual characteristics is that, while it lays eggs, it also has mammary glands used to feed its babies, not through nipples, but by milk -- which is sweat from its body.

The complete genome has provided us with the answers to how a few of the platypus' bizarre features emerged. At the same time, decoding the genome for platypus is important for improving our understanding of how other mammals evolved -- including us humans. It holds the key as to why we and other eutheria mammals evolved to become animals that give birth to live young instead of egg-laying animals," explains Professor Guojie Zhang of the Department of Biology.

"The platypus belongs to an ancient group of mammals -- monotremes -- which existed millions of years prior to the emergence of any modern-day mammal."

Read more here and here.

Wednesday, December 30, 2020

DNA Study of Caribbean Islanders Yields Surprises


These pieces reveal a range of styles and date to around 1200 A.D. 
(Corinne Hofman and Menno Hoogland / Florida Museum of Natural History)

New DNA studies have clarified migrations to islands of the Caribbean, but also raise additional questions. One question is why the European explorers of those island believed the native population to be much higher than the studies indicate?

This report on a technique developed by Harald Ringbauer, a postdoctoral fellow in the Reich Lab, explains that shared segments of DNA were used to estimate past population size, and showed that only about 10,000 to 50,000 people were living on two of the largest islands, Hispaniola and Puerto Rico, shortly before European arrival.

"While the heat and humidity of the tropics can quickly break down organic matter, the human body contains a lockbox of genetic material: a small, unusually dense part of the bone protecting the inner ear. Primarily using this structure, researchers extracted and analyzed DNA from 174 people who lived in the Caribbean and Venezuela between 400 and 3,100 years ago, combining the data with 89 previously sequenced individuals.

The team, which includes Caribbean-based scholars, received permission to carry out the genetic analysis from local governments and cultural institutions that acted as caretakers for the human remains. The authors also engaged representatives of Caribbean Indigenous communities in a discussion of their findings.

The genetic evidence offers new insights into the peopling of the Caribbean. The islands' first inhabitants, a group of stone tool-users, boated to Cuba about 6,000 years ago, gradually expanding eastward to other islands during the region's Archaic Age. Where they came from remains unclear -- while they are more closely related to Central and South Americans than to North Americans, their genetics do not match any particular Indigenous group."
The new study suggests the Caribeean islands were first populations by two waves. A group of migrants almost totally replaced the islands’ original population. Only 3 of the individuals sampled showed ancestry of two distinct populations.

Dr. William F. Keegan, whose work in the Caribbean spans more than 40 years, contributed to the study. He is curator at the Florida Museum of Natural History and co-senior author of the study. "The methods David's team developed helped address questions I didn't even know we could address."

The Arawak-speakers who arrived on these islands from northeast South America introduced ceramics about 2500 years ago. 
"During the Ceramic Age, Caribbean pottery underwent at least five marked shifts in style over 2,000 years. Ornate red pottery decorated with white painted designs gave way to simple, buff-colored vessels, while other pots were punctuated with tiny dots and incisions or bore sculpted animal faces that likely doubled as handles. Some archaeologists pointed to these transitions as evidence for new migrations to the islands. But DNA tells a different story, suggesting all of the styles were developed by descendants of the people who arrived in the Caribbean 2,500-3,000 years ago, though they may have interacted with and took inspiration from outsiders.

"That was a question we might not have known to ask had we not had an archaeological expert on our team," said co-first author Kendra Sirak, a postdoctoral fellow in the Reich Lab. "We document this remarkable genetic continuity across changes in ceramic style. We talk about 'pots vs. people,' and to our knowledge, it's just pots."

Read the full report here: Ancient DNA retells the story of Caribbean's first people, with a few plot twists; Pre-Columbian Pottery in the West Indies; Old World Migrations to the Americas

Thursday, December 17, 2020

The Crazy Colorado River

Recent geological research indicates that the Colorado river's route from the Colorado Plateau was influenced by tectonic deformation and vaciliating sea levels that caused a series of stops and starts between 6.3 and 4.8 million years ago. A team led by geologist Rebecca Dorsey of the University of Oregon has made a case for a complex history of the river, showing that, contrary to conventional thinking, a river's connection to the ocean is not a once-and-done deal.

"The birth of the Colorado River was more punctuated and filled with more uneven behavior than we expected," Dorsey said. "We've been trying to figure this out for years. This study is a major synthesis of regional stratigraphy, sedimentology and micropaleontology. By integrating these different datasets we are able to identify the different processes that controlled the birth and early evolution of this iconic river system."

Dorsey said that no single process controlled the Colorado River's initial route to the sea. "Different processes interacted in a surprisingly complicated sequence of events that led to the final integration of that river out to the ocean," she said.

The region covered in the research stretches from the southern Bouse Formation, near present-day Blythe, California, to the western Salton Trough north of where the river now trickles into the Gulf of California. The Bouse Formation and deposits in the Salton Trough have similar ages and span both sides of the San Andreas Fault, providing important clues to the river's origins.

The Colorado River starts in the peaks of the Rocky Mountain in the United States and flows into Mexico, where it empties into the Upper Sea of Cortez. Its natural course has varied over thousands of years, and the demand for water to serve an estimated 40 million people now exceeds the river’s supply, resulting in the desiccation of the Colorado’s last hundred miles.

The Colorado River's seven basin states are managing water under the Drought Contingency Plan, an agreement to safeguard water levels at the river's two main reservoirs, Lake Mead and Lake Powell. The two lakes are critical to providing water in times of drought. The Colorado River Basin states are Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming.

Thursday, November 26, 2020

Don't Forget the Cranberries!

An old-fashioned cranberry scoop. Today machines pump the berries from the bogs.

What is Thanksgiving dinner without cranberries? Some prefer the jellied form and others want the sauce made with whole berries. This traditional holiday condiment goes perfectly with the heavier foods enjoyed at the holidays. It is sweet and tart and sometimes a little spicey.

There are 100 varieties of cranberries, some of them heirloom varieties dating to the 1840's. The Ojibwa cultivated high-bush cranberries since the mid-17th century.

The red color of cranberries comes from pigments called anthocyanins.The range of red hues is due to the differing porportions of anthocyanins.

Cranberries have a high nutrient and antioxidant content. Research has linked the nutrients in cranberries to a lower risk of urinary tract infection, the prevention of some cancers, improved immune function, and decreased blood pressure.

It takes about 16 months for the cranberry to mature from a bud to a fruit ready to harvest. Most cranberries sold in the United States are grown in Wisconsin. Other states known for cranberry production include Massachusetts, New Jersey, and coastal areas of the Pacific Northwest.

Cranberries are grown in bogs which the growers sometimes flood to keep the leaves from drying out in the winter, and to make it easier to harvest. Once a bog is flooded, machines knock the berries into the water, and then harvesters don waders and corral the berries into an area where they can be pumped through a suction line and loaded on a truck.

Read more here

Saturday, November 7, 2020

Ice Age Plant Resurrected from Frozen Seeds

The oldest plant ever to be “resurrected” has been grown from 32,000-year-old seeds, beating the previous record holder of the Judean Palm by 30,000 years.

The narrow leafed perennial campion called Silene stenophylla is a small plant whose modern relatives are found in eastern Russia and northern Japan. This species that grows on stony cliffs or sandy shores. Once a year, it produces five-petalled flowers that range in color from white to pink to lilac.

A team of scientists from Russia, Hungary, and the United States recovered frozen Silene stenophylla seeds in 2007 while investigating about 70 ancient ground squirrel burrows or caches, hidden in permanently frozen deposits in northeastern Siberia.

The age of the seeds was estimated at between 20,000 and 40,000 years, dating the seeds to the Pleistocene epoch. More than 600,000 fruits and seeds thus preserved were located at the site.

Normally, the rodents would have eaten the food in their larders, but in this case a flood or some other weather event buried the area. The larders were at the level of the permafrost which resulted in the material freezing almost immediately. More than 600,000 fruits and seeds thus preserved were located at the site.

Years later, a team of scientists at the Russian Academy of Sciences successfully revived one of the plants: a flowering plant from a 32,000-year-old fruit!

Thursday, October 29, 2020

Witch's Hat or Priest's Hat?


Alice C. Linsley

Halloween may bring a few witches and wizards to your door and provide an opportunity to explain that the pointy hat originated among Hittite priests and kings. The children won't be that interested, but their parents might be!

The oldest known pointy hats were worn by ancient Hittite rulers and priests (1600-1180 BC). Today pointed black hats are associated with witches and wizards, but that is due mainly to popular movies. 

Below is a 3400-year gold pendant with a pointed hat found at Hattusa, the capital of the Hittite empire in ancient Anatolia (in modern Turkey).

This stone relief from Hattusa shows the Hittite King Suppiluliuma II who reigned from 1207-1178 BC). He wears a pointed crown.

This is a Hittite ruler-priest. The artifact dates to about 1600 BC. Note the ram horns on the hat, a symbol of divine appointment.

This stone relief was found at Yazilikaya, a Hittite shrine in modern Turkey in Chamber B. It shows King Tudhaliya IV wearing a pointed crown. It dates to between 1250 and 1220 BC.

This is a reproduction of reliefs that appear at Yazilikaya. The queen wears the solar crown (similar to that worn by Hathor, shown below).

Here again the king is seen wearing a pointed hat with horns. The ram's horns were sacred to the Hittites (People of Heth). Today the ram's horn, called shofar, is still blown as a horn at special ceremonies in Israel. God provided a ram for Abraham to sacrifice in place of his son. Abraham learned an important lesson there on Mount Moriah.

Saturday, October 24, 2020

Asian Hornets Kill Honeybees

The Pacific Northwest of the United States has seen an increase in the number of “murder hornets” or Asian giant hornets (Vespa mandarinia). This hornet is a threat to honeybees and is potentially dangerous to humans.

A party of several dozen Asian giant hornets can kill a whole bee hive and can kill thousands of bees in just a few hours.

This species feed their young the bodies of bees. They can sting over and over, in contrast to honeybees that die after its single-use stinger rips out of its body.

Another difference: Honeybees collect plant pollen as protein whereas the giant hornets slaughter the adult bees, then carry back the brood as food for their larvae.

Watch for the Latin terms vespa (hornet) and apis (bee). These terms distinguish between hornets and bees.