The storms of the previous day had moved eastward, leaving in their wake flooded farm fields and saturated roadside wetlands. At dusk, we loaded the Ford Escort wagon and headed south. We bumped along the maze of farm roads intent upon listening for croaks and snores in the night. At one roadside wetland, I heard my first congress of Spadefoot toads. The sound was deafening, invoking everything that a “congress of snoring toads” brings to mind. Around the corner, in a low spot of a corn field, a lone Spadefoot toad called for a mate; he was joined by a rather enthusiastic Copes Gray tree frog and several chorus frogs. The congress down the road provided a rolling bass to these more melodic anurans.
Wetlands exist in many different shapes and sizes and in many different geographies: coastal margins, mountain valleys, beaches and rocky shores, estuarine wetlands where tidal saltwater and freshwater mix, and inland wetlands. Some of them are ephemeral, some of them permanent. Wetlands serve many different functions, from providing habitat and food for plants and animals to offering protection from floods and maintaining water quality. One acre of one-foot deep wetland is estimated to hold 330,000 gallons of water. Coastal wetlands are important for reducing storm erosion by decreasing tidal surge and buffering the wind. In the US alone, this benefit has an estimated value of $23.2 billion dollars each year. Continue reading “Wetlands, Water Quality and Rapid Assays”
Warning: This blog contains stories about phantom serial killers, frankenfoods, mysteriously phosphorylated bands and unrequited ligations that may be disturbing to some people. Children or scientists prone to anxiety over irreproducible results should read this with their eyes shut.
Clouds hung low in the sky, and the late October wind howled between the buildings, rattling the window panes of the basement laboratory. The grackles cawed in desperate warning, their flocks changing the evening color palette from gray to black. I was as unsettled as the weather, watching my blot slosh back and forth. Continue reading “Control Samples: Three Terrifying Tales for Scientists”
The backlog of sexual assault kit samples in crime laboratories across the nation is a topic that hit the spotlight when a group of journalists uncovered the issue in an open records search of crime lab records in 2015. Reasons for the backlog include lack of staff, lack of funding, and simply, lack of time or a decision not to prosecute the case. Processing samples can be a labor-intensive process.
We recently interviewed Lynndsey R. Simon, Forensic Scientist II and Alternate CODIS Administrator from the Columbus Police Forensic Services Center to discuss some recent changes in sample processing in their laboratory that are helping to alleviate some of the backlog. She will be presenting a talk at the upcoming International Symposium on Human Identification (ISHI) in September.
The Columbus Police Forensic Services Center is a smaller forensic laboratory and according to Simon, one of the biggest challenges they face is strained resources. The DNA extraction and processing kits that forensic laboratories use are very expensive, and the number of DNA samples that laboratories are getting for DNA analysis are increasing. With limited resources and funding, maximizing efficiency and finding the best solutions for the laboratory becomes critical. Continue reading “Forensic Scientists Improve Sexual Assault Kit Turnaround Time with Y-Screening”
In April 2018, law enforcement officials announced the arrest of a suspect in the Golden State Killer case (New York Times ). Shortly after the announcement, those same law enforcement officers explained that detectives had used a public forensic genealogy web site to help identify the killer.
The keynote speaker for this year’s International Symposium on Human Identification (ISHI), Andrew Hessle, describes himself as a catalyst for big projects and ideas (1). In biology, catalysts are enzymes that alter the microenvironment and lower the energy of activation so that a chemical reaction that would proceed anyway happens at a much faster rate—making a reaction actually useful to the biological system in which it occurs.
In practical terms, Andrew Hessel is the person who helps us over our inertia. Instead of waiting for someone else, he sees a problem, gathers an interested group of people with diverse skills and perspectives, creates a microenvironment for these people to interact, and runs with them straight toward the problem. Boom. Reaction started.
Recently I wrote about the completion of the human genome sequencing project and the promise, problems and questions that the project has generated in the last decade and a half. One of the biggest realizations that I had from researching and writing that post is that our human genome makes us more alike than different at the molecular level, yet there is incredible variability in the human species around the globe.
I started to think about other things where the basic building blocks were the same, yet the final products were so very different—and I landed in the middle of a symphony orchestra.
Orchestras, if we look at the instruments that they have at their disposal, are very similar: dare I say 99% identical? For instance the instruments listed in the February 2017 roster for the New York Philharmonic Orchestra on Wikipedia (1) are very similar to the lists of instruments listed for the musicians of the Atlanta Symphony Orchestra on its web site (2). Numbers and groupings might vary, but the instruments are the same.
However no one would argue that the New York Philharmonic Orchestra and the Atlanta Symphony Orchestra and Chorus are interchangeable. Experiencing one is not the same as experiencing the other, and two separate experiences of either are often completely different.
There are 3 billion (3,000,000,000) bases in my genome—in each of the cells of my body. Likewise, Johanna, the writer who sits next to me at work also has 3 billion bases in her genome. Furthermore, our genomes are 99% the same. Still, that’s a lot of places where my genome can differ from hers, certainly enough to distinguish her DNA from mine if we were both suspected of stealing cookies from the cookie jar. The power of discrimination is what makes genetic identity using DNA markers such a powerful crime solving tool.
The completion of the human genome project in 2003 ushered in a tremendously fast-paced era of genomics research and technology. Just like computers shrank from expensive, building-filling mainframes to powerful hand-held devices we now call mobile phones, genome sequencing has progressed from floor-to-ceiling capillary electrophoresis units filling an entire building to bench top sequencers sitting in a corner of a lab. The $99 genome is a reality, and it’s in the hands of every consumer willing to spit into a tube.
Commercial DNA sequencing services are promising everything from revealing your true ancestry to determining your likelihood to develop dementia or various cancers. Is this progress and promise or is it something more sinister?
“The Great Book of Nature is written in mathematical language” –Galileo Galilei (1)
If mathematics is the language of the universe, might we find the ability to do math hard-wired in species?
Research in primates has demonstrated that even without training, humans and monkeys possess numerosity, the ability to assess the number of items in a set (2,3).
A paper in Current Biology from Wagener and colleagues provides evidence that crows are born with a subset of neurons that are “hard wired” to perceive the number of items in a set (4). This work provides yet more evidence supporting a hypothesis of an innate “number sense” that is provided by a specific group of “preprogrammed” neurons.
In this study, Wagener’s group measured the responses of single neurons in two “numerically naïve” crows to color dot arrays. They measured neurons in the endbrain region known as the niopallium caudolaterale (NCL), which is thought to be the avian analog of the primate prefrontal cortex. They found that 12% of the neurons in NCL specifically responded to numbers and that specific neurons responded to specific numbers of items with greater or lesser activity.
This is the first such study to investigate the idea of an innate “sense of number” in untrained vertebrates that are not primates, and as such it suggests that a hard-wired, innate “sense of number” is not a special feature of the complex cerebral cortex of the primate brain but is an adaptive property that evolved independently in the differently structured and evolved end brains of birds.
Many questions remain. Are there similarities in the actual neurons involved? What does learning do on a physiological level to these neurons: Increase their number, increase connections to them? What other vertebrates have similar innate mechanisms for assessing numbers of items? What about other members of the animal kingdom that need to have a sense of number for social or foraging behavior? How is it accomplished?
And finally, one last burning question, if birds are dinosaurs, does that mean that dinosaurs perished because they didn’t do their math homework? Asking for an eleven-year-old I know.
2018 has been designated “The Year of the Bird”, and beginning today, Friday, February 16, 2018, bird lovers around the world will grab their binoculars, fill their bird feeders, update their eBird app, and look toward the skies. The 21st Annual Great Backyard Bird Count, one of the largest and longest running citizen science projects, begins today, and you can be part of this grand event of data collection.
All it takes is a mobile device (or computer) to log your results, an account at gbbc.birdcount.org , and 15 minutes of your time during the four-day event.
Can’t tell a red-tailed hawk from a red-winged black bird? That’s okay. The GBBC web site provides a handy online bird guide. The web site also provides a guide for tricky bird IDs, including: Which Red Finch is it, Identifying Some Common Sparrows, and Identifying Doves.