The Battle of Alam Halfa in North Africa During WW II

The Battle of Alam Halfa in North Africa During WW II The Battle of Alam Halfa was fought from August 30 to September 5, 1942, during World War IIs Western Desert Campaign. Armies Commanders Allies Lieutenant General Bernard Montgomery4 divisions, XIII Corps, Eighth Army Axis Field Marshal Erwin Rommel6 divisions, Panzer Armee Afrika Background Leading to the Battle With the conclusion of the First Battle of El Alamein in July 1942, both British and Axis forces in North Africa paused to rest and refit. On the British side, Prime Minister Winston Churchill travelled to Cairo and relieved Commander-in-Chief Middle East Command General Claude Auchinleck and replacing him with General Sir Harold Alexander. Command of the British Eight Army at El Alamein ultimately was given to Lieutenant General Bernard Montgomery. Assessing the situation at El Alamein, Montgomery found that the front was constricted to a narrow line running from the coast to the impassable Qattara Depression. Montgomerys Plan To defend this line, three infantry divisions from XXX Corps were positioned on ridges running from the coast south to Ruweisat Ridge. To the south of the ridge, the 2nd New Zealand Division was similarly fortified along a line ending at Alam Nayil. In each case, the infantry was protected by extensive minefields and artillery support. The final twelve miles from Alam Nayil to the depression was featureless and difficult to defend. For this area, Montgomery ordered that minefields and wire be laid, with the 7th Motor Brigade Group and 4th Light Armoured Brigade of the 7th Armoured Division in position behind. When attacked, these two brigades were to inflict maximum casualties before falling back. Montgomery established his main defensive line along the ridges running east from Alam Nayil, most notably Alam Halfa Ridge. It was here that he positioned the bulk of his medium and heavy armor along with anti-tank guns and artillery. It was Montgomerys intention to entice Field Marshal Erwin Rommel to attack through this southern corridor and then defeat him in a defensive battle. As British forces assumed their positions, they were augmented by the arrival of reinforcements and new equipment as convoys reached Egypt. Rommels Advance Across the sands, Rommels situation was growing desperate as his supply situation worsened. While he advance across the desert had seen him win stunning victories over the British, it had badly extended his supply lines. Requesting 6,000 tons of fuel and 2,500 tons of ammunition from Italy for his planned offensive, Allied forces succeeded in sinking over half of the ships dispatched across the Mediterranean. As a result, only 1,500 tons of fuel reached Rommel by the end of August. Aware of Montgomerys growing strength, Rommel felt compelled to attack with the hope of winning a quick victory. Constrained by the terrain, Rommel planned to push the 15th and 21st Panzer Divisions, along with the 90th Light Infantry through the southern sector, while the bulk of his other forces demonstrated against the British front to the north. Once through the minefields, his men would push east before turning north to sever Montgomerys supply lines. Moving forward on the night of August 30, Rommels attack quickly encountered difficulty. Spotted by the Royal Air Force, British aircraft began attacking the advancing Germans as well as directing artillery fire on their line of advance. The Germans Held Reaching the minefields, the Germans found them to be much more extensive than anticipated. Slowly working through them, they came under intense fire from the 7th Armoured Division and British aircraft which exacted a high toll, including wounding General Walther Nehring, commander of the Afrika Korps. Despite these difficulties, the Germans were able to clear the minefields by noon the next day and began pressing east. Eager to make up lost time and under constant harassing attacks from 7th Armoured, Rommel ordered his troops to turn north earlier than planned. This maneuver directed the assault against the 22nd Armoured Brigades positions on Alam Halfa Ridge. Moving north, the Germans were met with intense fire from the British and were halted. A flank attack against the British left was stopped by heavy fire from anti-tank guns. Stymied and short on fuel, General Gustav von Vaerst, now leading the Afrika Korps, pulled back for the night. Attacked through the night by British aircraft, German operations on September 1 were limited as 15th Panzer had a dawn attack checked by the 8th Armoured Brigade and Rommel began moving Italian troops into the southern front. Under constant air attack during the night and into the morning hours of September 2, Rommel realized that the offensive had failed and decided to withdraw west. His situation was made more desperate when a column of British armored cars badly mauled one of his supply convoys near Qaret el Himeimat. Realizing his adversarys intentions, Montgomery began formulating plans for counterattacks with the 7th Armoured and 2nd New Zealand. In both cases, he emphasized that neither division should incur losses that would preclude them from taking part in a future offensive. While a major push from 7th Armoured never developed, the New Zealanders attacked south at 10:30 PM on September 3. While the veteran 5th New Zealand Brigade had success against the defending Italians, an assault by the green 132nd Brigade collapsed due to confusion and fierce enemy resistance. Not believing a further attack would succeed, Montgomery cancelled further offensive operations the next day. As a result, the German and Italian troops were able to retreat back to their lines, though under frequent air attack. The Battles Aftermath The victory at Alam Halfa cost Montgomery 1,750 killed, wounded, and missing as well as 68 tanks and 67 aircraft. Axis losses totaled around 2,900 killed, wounded, and missing along with 49 tanks, 36 aircraft, 60 guns, and 400 transport vehicles. Often overshadowed by the First and Second Battles of El Alamein, Alam Halfa represented the last significant offensive launched by Rommel in North Africa. Far from his bases and with his supply lines crumbling, Rommel was forced to move to the defensive as British strength in Egypt grew. In the wake of the battle, Montgomery was criticized for not pressing harder to cut off and destroy the Afrika Korps when it was isolated on his southern flank. He responded by stating that Eighth Army was still in the process of reforming and lacked the logistical network to support the exploitation of such a victory. Also, he was adamant that he wished to preserve British strength for a planned offensive rather than risk it in counterattacks against Rommels defenses. Having shown restraint at Alam Halfa, Montgomery moved to the attack in October when he opened the Second Battle of El Alamein. Sources Defensive Military Structures in Action: Historical ExamplesBBC: Peoples War - Battle of Alam Halfa

Evo Devo in the Study of Biology

Evo Devo in the Study of Biology Have you heard anyone ever talk about evo-devo? Does it sound like some sort of synthesizer-heavy band from the 1980s? It is actually a relatively new field in the realm of evolutionary biology that explains how species, that start out so similarly, become so diverse as they develop. Evo devo stands for evolutionary developmental biology and has just started being included in the Modern Synthesis of the Theory of Evolution within the past few decades. This field of study encompasses many different ideas and some scientists disagree on what all should be included. However, all who study evo devo agree that the foundation of the field is based on the gene level of inheritance which leads to microevolution. As an embryo develops, certain genes need to be activated in order for the traits carried on that gene to be expressed. Most of the time, there are biological clues for these genes to turn on based on the age of the embryo. Sometimes, environmental conditions can trigger the expression of the developmental genes as well. Not only do these triggers turn on the gene, they also direct the gene on how to be expressed. There are subtle differences between the arms of different animals that are determined by how the genes that carry the trait for limb development are expressed. The same gene that creates a human arm can also create a sparrows wing or a grasshoppers leg. They are not different genes, as previously thought by scientists. Evo Devo and the Theory of Evolution What does this mean for the Theory of Evolution? First and foremost, it lends credibility to the idea that all life on Earth came from a common ancestor. This common ancestor had the exact same genes we see today in all of our modern species. It is not the genes that have evolved over time. Instead, it is how and when (and if) those genes are expressed that has evolved. Also, it helps to give an explanation for how the beak shape of Darwins finches on the Galapagos Islands could have evolved. Natural Selection is the mechanism that chooses which of these ancient genes are expressed and ultimately how they are expressed. Over time, the differences in gene expression led to the great diversity and large numbers of different species we see in the world today. The theory of evo devo also explains why so few genes can create so many complex organisms. It turns out that the same genes are used over and over again but in different ways. The genes that are expressed to create arms in humans may also be used to create legs or even a human heart. Therefore, it is more important how the genes are expressed than how many genes are present. Developmental genes across species are the same and can be expressed in a nearly unlimited number of ways. Embryos of many different species are nearly indistinguishable from each other at the early stages before these developmental genes are turned on. Early embryos of all species have gills or gill pouches and similar overall shapes. It is crucial for these developmental genes to be activated correctly at the right time and at the right place. Scientists have been able to manipulate genes in fruit flies and other species to make limbs and other body parts grow in different places on the body. This proved these genes control many different parts of embryo development. The field of evo devo reaffirms the validity of using animals for medical research. An argument against animal research is the obvious difference in complexity and structure between humans and the research animals. However, with such similarities on a molecular and gene level, studying those animals can give insight into the human, and particularly the development and gene activation of humans.